diff --git a/build.js b/build.js
old mode 100644
new mode 100755
index d0302e2..8f82ffb
--- a/build.js
+++ b/build.js
@@ -1,3 +1,5 @@
+#!/usr/bin/env node
+
 var fs = require('fs')
 var pegjs = require('pegjs')
 var overrideAction = require('pegjs-override-action')
@@ -6,10 +8,12 @@ var input     = __dirname + '/grammar.pegjs'
 var output    = __dirname + '/parser.js'
 var overrides = __dirname + '/overrides.js'
 
+var trace = false;
 if (require.main === module) {
   if (process.argv[2] == '-w') {
     watch()
   } else {
+    if (process.argv[2] == '-t') trace = true;
     console.log(getSource())
   }
 }
@@ -19,6 +23,7 @@ function getSource () {
   var grammar = fs.readFileSync(input, 'utf8')
   var parserSource = pegjs.buildParser(grammar, {
     output: "source",
+    trace: trace,
     allowedStartRules: [
       'script',
       'command',
diff --git a/grammar.pegjs b/grammar.pegjs
index 0de4795..c099b6d 100644
--- a/grammar.pegjs
+++ b/grammar.pegjs
@@ -7,7 +7,8 @@ statementList
    space* last:controlOperator? spaceNL*
 
 statement
- = statement:( subshell
+ = statement:(arithmeticStatement
+             / subshell
              / bashExtensions
              / command
              / variableAssignment
@@ -20,6 +21,9 @@ statement
 chainedStatement
  = operator:('&&' / '||') spaceNL* statement:statement
 
+arithmeticStatement "an arithmetic statement"
+ = "((" space* expression:arithmetic space* "))"
+
 subshell "a subshell"
  = "(" space* statements:statementList  space* ")"
 
@@ -85,6 +89,7 @@ concatenation "concatenation of strings and/or variables"
           / bareword
           / environmentVariable
           / variableSubstitution
+          / arithmeticSubstitution
           / commandSubstitution
           / singleQuote
           / doubleQuote
@@ -123,7 +128,8 @@ doubleQuoteMeta
  = '"' / '$' / '`'
 
 expandsInQuotes
- = commandSubstitution
+ = arithmeticSubstitution
+ / commandSubstitution
  / environmentVariable
  / variableSubstitution
 
@@ -140,6 +146,9 @@ commandSubstitution
 parenCommandSubstitution
  = '$(' commands:statementList ')'
 
+arithmeticSubstitution
+ = '$((' expression:arithmetic '))'
+
 backQuote
  = '`' input:backQuoteChar+ '`'
 
@@ -200,8 +209,109 @@ keyword
    )
    ( spaceNL+ / EOF )
 
+// http://www.gnu.org/software/bash/manual/html_node/Shell-Arithmetic.html
+arithmetic "an arithmetic expression"
+ = expression:aComma { return expression }
+
+aComma "a sequence of arithmetic expressions"
+ = head:aAssign tail:( spaceNL* "," spaceNL* expr:aAssign { return expr } )*
+
+aAssign "an arithmetic assignment"
+ = left:aCond spaceNL* operator:( "=" !"=" / "*=" / "/=" / "%=" / "+=" / "-=" / "<<=" / ">>=" / "&=" / "^=" / "|=" ) spaceNL* right:aAssign
+ / other:aCond
+
+aCond "an arithmetic conditional expression"
+ = test:aLogicalOr spaceNL* "?" spaceNL* consequent:aAssign spaceNL* ":" spaceNL* alternate:aAssign
+ / other:aLogicalOr
+
+aLogicalOr "an arithmetic logical or"
+ = head:aLogicalAnd tail:(spaceNL* op:"||" spaceNL* node:aLogicalAnd { return {op: op, node: node} })*
+
+aLogicalAnd "an arithmetic logical and"
+ = head:aBitwiseOr tail:(spaceNL* op:"&&" spaceNL* node:aBitwiseOr { return {op: op, node: node} })*
+
+aBitwiseOr
+ = head:aBitwiseXor tail:(spaceNL* op:"|" ![|=] spaceNL* node:aBitwiseXor { return {op: op, node: node} })*
+
+aBitwiseXor
+ = head:aBitwiseAnd tail:(spaceNL* op:"^" !"=" spaceNL* node:aBitwiseAnd { return {op: op, node: node} })*
+
+aBitwiseAnd
+ = head:aEquality tail:(spaceNL* op:"&" ![&=] spaceNL* node:aEquality { return {op: op, node: node} })*
+
+aEquality
+ = head:aComparison tail:(spaceNL* op:( "==" / "!=" ) spaceNL* node:aComparison { return {op: op, node: node} })*
+
+aComparison
+ = head:aBitwiseShift tail:(spaceNL* op:( "<=" / ">=" / (v:"<" !"<" { return v }) / (v:">" !">" { return v }) ) spaceNL* node:aBitwiseShift { return {op: op, node: node} })*
+
+aBitwiseShift
+ = head:aAddSubtract tail:(spaceNL* op:( "<<" / ">>" ) !"=" spaceNL* node:aAddSubtract { return {op: op, node: node} })*
+
+aAddSubtract
+ = head:aMultDivModulo tail:(spaceNL* op:( "+" / "-" ) !"=" spaceNL* node:aMultDivModulo { return {op: op, node: node} })*
+
+aMultDivModulo
+ = head:aExponent tail:(spaceNL* op:( (v:"*" !"*" { return v }) / "/" / "%") !"=" spaceNL* node:aExponent { return {op: op, node: node} })*
+
+aExponent
+ = head:aNegation tail:(spaceNL* op:"**" spaceNL* node:aNegation { return {op: op, node: node} })*
+
+aNegation
+ = operator:( "!" / "~" ) spaceNL* argument:aNegation
+ / other:aUnary
+
+aUnary
+ = operator:( (op:"+" ![+=]) { return op } / (op:"-" ![-=]) { return op } ) spaceNL* argument:aUnary
+ / other:aPreIncDec
+
+aPreIncDec
+ = operator:( "++" / "--" ) spaceNL* argument:aPreIncDec
+ / other:aPostIncDec
+
+aPostIncDec
+ = argument:aMemberExpr operators:(spaceNL* op:( "++" / "--" ) { return op })+
+ / other:aMemberExpr
+
+
+aMemberExpr
+  = head:aParenExpr tail:(spaceNL* "[" property:arithmetic "]" { return property })*
+
+aParenExpr
+ = '(' spaceNL* value:arithmetic spaceNL* ')' { return value }
+ / other:aLiteral { return other }
+
+aBareword "arithmetic variable"
+  = !'#' name:aBarewordChar+
+
+aBarewordChar
+  = '\\' chr:aBarewordMeta { return chr }
+  / !aBarewordMeta chr:.   { return chr }
+
+aBarewordMeta = [$"';&<>\n()\[\]*?|`:+^\- ]
+
+aConcatenation "concatenation of strings and/or variables"
+  = pieces:( aBareword
+           / environmentVariable
+           / variableSubstitution
+           / arithmeticSubstitution
+           / commandSubstitution
+           / singleQuote
+           / doubleQuote
+           )+
+
+aLiteral
+ = val:aNumber   { return val }
+ / val:aConcatenation { return val }
+
+aNumber
+ = "0" [xX] digits:[0-9a-fA-Z]+
+ / base:[0-9]+ "#" digits:[0-9a-zA-Z]+
+ / "0" digits:[0-7]+
+ / digits:[0-9]+
+
 continuationStart
- = &( keyword / '"' / "'" / '`' / "$(" / "${" ) .*
+ = &( keyword / '"' / "'" / '`' / "$(" / "$((" / "${" ) .*
 
 EOF
  = !.
diff --git a/overrides.js b/overrides.js
index 3c024ee..c4707da 100644
--- a/overrides.js
+++ b/overrides.js
@@ -67,6 +67,14 @@ exports.initializer = [
       type: 'concatenation',
       pieces: result
     }
+  },
+  // create a nested tree from a list of same-precedence operators
+  function buildTree(head, tail, createNode) {
+    var result = head;
+    for (var i = 0, l = tail.length; i < l; i++) {
+      result = createNode(result, tail[i]);
+    }
+    return result;
   }
 ].join('\n')
 
@@ -97,6 +105,13 @@ rules.statementList = function (first, tail, last) {
   }
 }
 
+rules.arithmeticStatement = function (expression) {
+  return {
+    type: 'arithmeticStatement',
+    expression: expression,
+  }
+}
+
 rules.subshell = function (statements) {
   return {
     type: 'subshell',
@@ -267,6 +282,13 @@ rules.parenCommandSubstitution = function (commands) {
   }
 }
 
+rules.arithmeticSubstitution = function (expression) {
+  return {
+    type: 'arithmeticSubstitution',
+    expression: expression
+  };
+}
+
 rules.backQuote = function (input) {
   return { type: 'commandSubstitution', commands: parse(input.join('')) }
 }
@@ -304,3 +326,140 @@ rules.redirectFd = function (fd, op, filename) {
     filename: filename
   }
 }
+
+rules.aBareword = function (name) {
+  // TODO: check if array
+  return {type: 'variable', name: name.join('')}
+}
+
+rules.aConcatenation = function (pieces) {
+  // TODO: if it's an array, nest it
+  return flattenConcatenation(pieces)
+}
+
+rules.aNumber = [
+  function (digits) {
+    return {type: 'number', value: parseInt(digits.join(''), 16)}
+  },
+  function (base, digits) {
+    return {type: 'number', value: parseInt(digits.join(''), parseInt(base.join(''), 10))}
+  },
+  function (digits) {
+    return {type: 'number', value: parseInt(digits.join(''), 8)}
+  },
+  function (digits) {
+    return {type: 'number', value: parseInt(digits.join(''), 10)}
+  }
+]
+
+rules.aComma = function (head, tail) {
+  if (tail.length) {
+    return {
+      type: 'arithmeticSequence',
+      expressions: [head].concat(tail)
+    }
+  }
+  return head
+}
+
+function other(other) { return other }
+
+rules.aCond = [
+  function (test, consequent, alternate) {
+    return {
+      type: 'arithmeticConditional',
+      test: test,
+      consequent: consequent,
+      alternate: alternate
+    }
+  }, other
+]
+
+rules.aAssign = [
+  function (left, operator, right) {
+    return {
+      type: 'arithmeticAssignment',
+      left: left,
+      operator: operator,
+      right: right
+    }
+  }, other
+]
+
+rules.aLogicalOr =
+rules.aLogicalAnd =
+function (head, tail) {
+  return buildTree(head, tail, function (child, current) {
+    return {
+      type: 'arithmeticLogical',
+      operator: current.op,
+      left: child,
+      right: current.node
+    }
+  });
+}
+
+rules.aBitwiseOr =
+rules.aBitwiseXor =
+rules.aBitwiseAnd =
+rules.aEquality =
+rules.aComparison =
+rules.aBitwiseShift =
+rules.aAddSubtract =
+rules.aMultDivModulo =
+rules.aExponent =
+function (head, tail) {
+  return buildTree(head, tail, function (child, current) {
+    return {
+      type: 'arithmeticBinary',
+      operator: current.op,
+      left: child,
+      right: current.node
+    }
+  });
+}
+
+rules.aNegation = rules.aUnary =
+[
+  function (operator, argument) {
+    return {
+      type: 'arithmeticUnary',
+      operator: operator,
+      argument: argument
+    }
+  }, other
+]
+
+rules.aPreIncDec = [
+  function (operator, argument) {
+    return {
+      type: 'arithmeticUpdate',
+      operator: operator,
+      argument: argument,
+      prefix: true
+    }
+  }, other
+]
+
+rules.aPostIncDec = [
+  function (argument, operators) {
+    return buildTree(argument, operators, function (node, operator) {
+      return {
+        type: 'arithmeticUpdate',
+        operator: operator,
+        argument: node,
+        prefix: false
+      }
+    });
+  }, other
+]
+
+rules.aMemberExpr = function (head, tail) {
+  return buildTree(head, tail, function (child, current) {
+    return {
+      type: 'arithmeticMemberExpression',
+      array: child,
+      property: current
+    }
+  });
+}
diff --git a/package.json b/package.json
index 734be20..b9db322 100644
--- a/package.json
+++ b/package.json
@@ -10,7 +10,7 @@
   },
   "scripts": {
     "test": "tape tests/*.js",
-    "watch": "npm run prepublish && node build.js -w",
+    "watch": "npm run prepublish && echo watching... && node build.js -w",
     "prepublish": "node build.js > parser.js"
   },
   "testling": {
@@ -35,10 +35,10 @@
     }
   },
   "devDependencies": {
+    "markdown-code-blocks": "0.0.1",
     "pegjs": "~0.9.0",
     "pegjs-override-action": "0.2.3",
     "tape": "^4.5.1",
-    "markdown-code-blocks": "0.0.1",
     "xtend": "~2.1.1"
   },
   "repository": {
diff --git a/parser.js b/parser.js
index 48f4f91..4377d37 100644
--- a/parser.js
+++ b/parser.js
@@ -92,19 +92,30 @@ var parser=(function() {
         peg$c7 = function(operator, statement) {
           return [operator, statement]
         },
-        peg$c8 = { type: "other", description: "a subshell" },
-        peg$c9 = "(",
-        peg$c10 = { type: "literal", value: "(", description: "\"(\"" },
-        peg$c11 = ")",
-        peg$c12 = { type: "literal", value: ")", description: "\")\"" },
-        peg$c13 = function(statements) {
+        peg$c8 = { type: "other", description: "an arithmetic statement" },
+        peg$c9 = "((",
+        peg$c10 = { type: "literal", value: "((", description: "\"((\"" },
+        peg$c11 = "))",
+        peg$c12 = { type: "literal", value: "))", description: "\"))\"" },
+        peg$c13 = function(expression) {
+          return {
+            type: 'arithmeticStatement',
+            expression: expression,
+          }
+        },
+        peg$c14 = { type: "other", description: "a subshell" },
+        peg$c15 = "(",
+        peg$c16 = { type: "literal", value: "(", description: "\"(\"" },
+        peg$c17 = ")",
+        peg$c18 = { type: "literal", value: ")", description: "\")\"" },
+        peg$c19 = function(statements) {
           return {
             type: 'subshell',
             statements: statements,
           }
         },
-        peg$c14 = { type: "other", description: "a single command" },
-        peg$c15 = function(pre, name, post, pipe) {
+        peg$c20 = { type: "other", description: "a single command" },
+        peg$c21 = function(pre, name, post, pipe) {
           var command = {
             type: 'command',
             command: name,
@@ -135,19 +146,19 @@ var parser=(function() {
 
           return command
         },
-        peg$c16 = function(test) {
+        peg$c22 = function(test) {
           return test
         },
-        peg$c17 = { type: "other", description: "an if/elif/else statement" },
-        peg$c18 = "if",
-        peg$c19 = { type: "literal", value: "if", description: "\"if\"" },
-        peg$c20 = "then",
-        peg$c21 = { type: "literal", value: "then", description: "\"then\"" },
-        peg$c22 = "else",
-        peg$c23 = { type: "literal", value: "else", description: "\"else\"" },
-        peg$c24 = "fi",
-        peg$c25 = { type: "literal", value: "fi", description: "\"fi\"" },
-        peg$c26 = function(test, body, elifBlocks, elseBody) {
+        peg$c23 = { type: "other", description: "an if/elif/else statement" },
+        peg$c24 = "if",
+        peg$c25 = { type: "literal", value: "if", description: "\"if\"" },
+        peg$c26 = "then",
+        peg$c27 = { type: "literal", value: "then", description: "\"then\"" },
+        peg$c28 = "else",
+        peg$c29 = { type: "literal", value: "else", description: "\"else\"" },
+        peg$c30 = "fi",
+        peg$c31 = { type: "literal", value: "fi", description: "\"fi\"" },
+        peg$c32 = function(test, body, elifBlocks, elseBody) {
           return {
             type: 'ifElse',
             test: test,
@@ -156,41 +167,41 @@ var parser=(function() {
             elseBody: elseBody ? elseBody[1] : null,
           }
         },
-        peg$c27 = "elif",
-        peg$c28 = { type: "literal", value: "elif", description: "\"elif\"" },
-        peg$c29 = function(test, body) {
+        peg$c33 = "elif",
+        peg$c34 = { type: "literal", value: "elif", description: "\"elif\"" },
+        peg$c35 = function(test, body) {
           return {
             type: 'ifElse',
             test: test,
             body: body
           }
         },
-        peg$c30 = { type: "other", description: "a while/until loop" },
-        peg$c31 = "while",
-        peg$c32 = { type: "literal", value: "while", description: "\"while\"" },
-        peg$c33 = "until",
-        peg$c34 = { type: "literal", value: "until", description: "\"until\"" },
-        peg$c35 = "do",
-        peg$c36 = { type: "literal", value: "do", description: "\"do\"" },
-        peg$c37 = "done",
-        peg$c38 = { type: "literal", value: "done", description: "\"done\"" },
-        peg$c39 = function(kind, test, body) {
+        peg$c36 = { type: "other", description: "a while/until loop" },
+        peg$c37 = "while",
+        peg$c38 = { type: "literal", value: "while", description: "\"while\"" },
+        peg$c39 = "until",
+        peg$c40 = { type: "literal", value: "until", description: "\"until\"" },
+        peg$c41 = "do",
+        peg$c42 = { type: "literal", value: "do", description: "\"do\"" },
+        peg$c43 = "done",
+        peg$c44 = { type: "literal", value: "done", description: "\"done\"" },
+        peg$c45 = function(kind, test, body) {
           return {
             type: kind + 'Loop',
             test: test,
             body: body
           }
         },
-        peg$c40 = { type: "other", description: "a for loop" },
-        peg$c41 = "for",
-        peg$c42 = { type: "literal", value: "for", description: "\"for\"" },
-        peg$c43 = "in",
-        peg$c44 = { type: "literal", value: "in", description: "\"in\"" },
-        peg$c45 = ";",
-        peg$c46 = { type: "literal", value: ";", description: "\";\"" },
-        peg$c47 = "\n",
-        peg$c48 = { type: "literal", value: "\n", description: "\"\\n\"" },
-        peg$c49 = function(loopVar, subjects, body) {
+        peg$c46 = { type: "other", description: "a for loop" },
+        peg$c47 = "for",
+        peg$c48 = { type: "literal", value: "for", description: "\"for\"" },
+        peg$c49 = "in",
+        peg$c50 = { type: "literal", value: "in", description: "\"in\"" },
+        peg$c51 = ";",
+        peg$c52 = { type: "literal", value: ";", description: "\";\"" },
+        peg$c53 = "\n",
+        peg$c54 = { type: "literal", value: "\n", description: "\"\\n\"" },
+        peg$c55 = function(loopVar, subjects, body) {
           return {
             type: 'forLoop',
             loopVariable: loopVar,
@@ -198,136 +209,144 @@ var parser=(function() {
             body: body
           }
         },
-        peg$c50 = { type: "other", description: "time builtin" },
-        peg$c51 = "time",
-        peg$c52 = { type: "literal", value: "time", description: "\"time\"" },
-        peg$c53 = "-",
-        peg$c54 = { type: "literal", value: "-", description: "\"-\"" },
-        peg$c55 = /^[a-z]/,
-        peg$c56 = { type: "class", value: "[a-z]", description: "[a-z]" },
-        peg$c57 = function(flags, statements) {
+        peg$c56 = { type: "other", description: "time builtin" },
+        peg$c57 = "time",
+        peg$c58 = { type: "literal", value: "time", description: "\"time\"" },
+        peg$c59 = "-",
+        peg$c60 = { type: "literal", value: "-", description: "\"-\"" },
+        peg$c61 = /^[a-z]/,
+        peg$c62 = { type: "class", value: "[a-z]", description: "[a-z]" },
+        peg$c63 = function(flags, statements) {
           return {
             type: 'time',
             flags: flags,
             command: statements
           }
         },
-        peg$c58 = { type: "other", description: "declare builtin" },
-        peg$c59 = "declare",
-        peg$c60 = { type: "literal", value: "declare", description: "\"declare\"" },
-        peg$c61 = "typeset",
-        peg$c62 = { type: "literal", value: "typeset", description: "\"typeset\"" },
-        peg$c63 = /^[^\n]/,
-        peg$c64 = { type: "class", value: "[^\\n]", description: "[^\\n]" },
-        peg$c65 = { type: "other", description: "a variable assignment" },
-        peg$c66 = "=",
-        peg$c67 = { type: "literal", value: "=", description: "\"=\"" },
-        peg$c68 = function(name, value) {
+        peg$c64 = { type: "other", description: "declare builtin" },
+        peg$c65 = "declare",
+        peg$c66 = { type: "literal", value: "declare", description: "\"declare\"" },
+        peg$c67 = "typeset",
+        peg$c68 = { type: "literal", value: "typeset", description: "\"typeset\"" },
+        peg$c69 = /^[^\n]/,
+        peg$c70 = { type: "class", value: "[^\\n]", description: "[^\\n]" },
+        peg$c71 = { type: "other", description: "a variable assignment" },
+        peg$c72 = "=",
+        peg$c73 = { type: "literal", value: "=", description: "\"=\"" },
+        peg$c74 = function(name, value) {
           return {type: 'variableAssignment', name: name, value: value}
         },
-        peg$c69 = { type: "other", description: "command name" },
-        peg$c70 = function(name) {
+        peg$c75 = { type: "other", description: "command name" },
+        peg$c76 = function(name) {
           return name
         },
-        peg$c71 = "[[",
-        peg$c72 = { type: "literal", value: "[[", description: "\"[[\"" },
-        peg$c73 = "[",
-        peg$c74 = { type: "literal", value: "[", description: "\"[\"" },
-        peg$c75 = { type: "other", description: "command argument" },
-        peg$c76 = { type: "other", description: "concatenation of strings and/or variables" },
-        peg$c77 = function(pieces) {
+        peg$c77 = "[[",
+        peg$c78 = { type: "literal", value: "[[", description: "\"[[\"" },
+        peg$c79 = "[",
+        peg$c80 = { type: "literal", value: "[", description: "\"[\"" },
+        peg$c81 = { type: "other", description: "command argument" },
+        peg$c82 = { type: "other", description: "concatenation of strings and/or variables" },
+        peg$c83 = function(pieces) {
           return flattenConcatenation(pieces)
         },
-        peg$c78 = { type: "other", description: "bareword" },
-        peg$c79 = "#",
-        peg$c80 = { type: "literal", value: "#", description: "\"#\"" },
-        peg$c81 = function(cs) { return literal(cs) },
-        peg$c82 = "\\",
-        peg$c83 = { type: "literal", value: "\\", description: "\"\\\\\"" },
-        peg$c84 = function(chr) { return chr },
-        peg$c85 = { type: "any", description: "any character" },
-        peg$c86 = /^[$"';&<>\n()[*?|` ]/,
-        peg$c87 = { type: "class", value: "[$\"';&<>\\n()\\[*?|` ]", description: "[$\"';&<>\\n()\\[*?|` ]" },
-        peg$c88 = "*",
-        peg$c89 = { type: "literal", value: "*", description: "\"*\"" },
-        peg$c90 = "?",
-        peg$c91 = { type: "literal", value: "?", description: "\"?\"" },
-        peg$c92 = function() {
+        peg$c84 = { type: "other", description: "bareword" },
+        peg$c85 = "#",
+        peg$c86 = { type: "literal", value: "#", description: "\"#\"" },
+        peg$c87 = function(cs) { return literal(cs) },
+        peg$c88 = "\\",
+        peg$c89 = { type: "literal", value: "\\", description: "\"\\\\\"" },
+        peg$c90 = function(chr) { return chr },
+        peg$c91 = { type: "any", description: "any character" },
+        peg$c92 = /^[$"';&<>\n()[*?|` ]/,
+        peg$c93 = { type: "class", value: "[$\"';&<>\\n()\\[*?|` ]", description: "[$\"';&<>\\n()\\[*?|` ]" },
+        peg$c94 = "*",
+        peg$c95 = { type: "literal", value: "*", description: "\"*\"" },
+        peg$c96 = "?",
+        peg$c97 = { type: "literal", value: "?", description: "\"?\"" },
+        peg$c98 = function() {
           return {
             type: 'glob',
             value: text()
           }
         },
-        peg$c93 = "]",
-        peg$c94 = { type: "literal", value: "]", description: "\"]\"" },
-        peg$c95 = "$",
-        peg$c96 = { type: "literal", value: "$", description: "\"$\"" },
-        peg$c97 = "{",
-        peg$c98 = { type: "literal", value: "{", description: "\"{\"" },
-        peg$c99 = "}",
-        peg$c100 = { type: "literal", value: "}", description: "\"}\"" },
-        peg$c101 = "'",
-        peg$c102 = { type: "literal", value: "'", description: "\"'\"" },
-        peg$c103 = /^[^']/,
-        peg$c104 = { type: "class", value: "[^']", description: "[^']" },
-        peg$c105 = function(inner) { return literal(inner) },
-        peg$c106 = "\"",
-        peg$c107 = { type: "literal", value: "\"", description: "\"\\\"\"" },
-        peg$c108 = function(contents) {
+        peg$c99 = "]",
+        peg$c100 = { type: "literal", value: "]", description: "\"]\"" },
+        peg$c101 = "$",
+        peg$c102 = { type: "literal", value: "$", description: "\"$\"" },
+        peg$c103 = "{",
+        peg$c104 = { type: "literal", value: "{", description: "\"{\"" },
+        peg$c105 = "}",
+        peg$c106 = { type: "literal", value: "}", description: "\"}\"" },
+        peg$c107 = "'",
+        peg$c108 = { type: "literal", value: "'", description: "\"'\"" },
+        peg$c109 = /^[^']/,
+        peg$c110 = { type: "class", value: "[^']", description: "[^']" },
+        peg$c111 = function(inner) { return literal(inner) },
+        peg$c112 = "\"",
+        peg$c113 = { type: "literal", value: "\"", description: "\"\\\"\"" },
+        peg$c114 = function(contents) {
           var pieces = contents.map(function (it) {
             return isArray(it) ? literal(it) : it
           })
           return flattenConcatenation(pieces)
         },
-        peg$c109 = "\\\\",
-        peg$c110 = { type: "literal", value: "\\\\", description: "\"\\\\\\\\\"" },
-        peg$c111 = function() { return '\\' },
-        peg$c112 = "`",
-        peg$c113 = { type: "literal", value: "`", description: "\"`\"" },
-        peg$c114 = function(name) {
+        peg$c115 = "\\\\",
+        peg$c116 = { type: "literal", value: "\\\\", description: "\"\\\\\\\\\"" },
+        peg$c117 = function() { return '\\' },
+        peg$c118 = "`",
+        peg$c119 = { type: "literal", value: "`", description: "\"`\"" },
+        peg$c120 = function(name) {
           return {type: 'variable', name: name}
         },
-        peg$c115 = /^[a-zA-Z0-9_]/,
-        peg$c116 = { type: "class", value: "[a-zA-Z0-9_]", description: "[a-zA-Z0-9_]" },
-        peg$c117 = function() { return text() },
-        peg$c118 = "${",
-        peg$c119 = { type: "literal", value: "${", description: "\"${\"" },
-        peg$c120 = /^[^}]/,
-        peg$c121 = { type: "class", value: "[^}]", description: "[^}]" },
-        peg$c122 = function(expr) {
+        peg$c121 = /^[a-zA-Z0-9_]/,
+        peg$c122 = { type: "class", value: "[a-zA-Z0-9_]", description: "[a-zA-Z0-9_]" },
+        peg$c123 = function() { return text() },
+        peg$c124 = "${",
+        peg$c125 = { type: "literal", value: "${", description: "\"${\"" },
+        peg$c126 = /^[^}]/,
+        peg$c127 = { type: "class", value: "[^}]", description: "[^}]" },
+        peg$c128 = function(expr) {
           return {
             type:        'variableSubstitution',
             expression:  join(expr), // TODO subParser
           }
         },
-        peg$c123 = "$(",
-        peg$c124 = { type: "literal", value: "$(", description: "\"$(\"" },
-        peg$c125 = function(commands) {
+        peg$c129 = "$(",
+        peg$c130 = { type: "literal", value: "$(", description: "\"$(\"" },
+        peg$c131 = function(commands) {
           return {
             type: 'commandSubstitution',
             commands: commands
           }
         },
-        peg$c126 = function(input) {
+        peg$c132 = "$((",
+        peg$c133 = { type: "literal", value: "$((", description: "\"$((\"" },
+        peg$c134 = function(expression) {
+          return {
+            type: 'arithmeticSubstitution',
+            expression: expression
+          };
+        },
+        peg$c135 = function(input) {
           return { type: 'commandSubstitution', commands: parse(input.join('')) }
         },
-        peg$c127 = "\\`",
-        peg$c128 = { type: "literal", value: "\\`", description: "\"\\\\`\"" },
-        peg$c129 = function() { return '`' },
-        peg$c130 = /^[<>]/,
-        peg$c131 = { type: "class", value: "[<>]", description: "[<>]" },
-        peg$c132 = function(rw, commands) {
+        peg$c136 = "\\`",
+        peg$c137 = { type: "literal", value: "\\`", description: "\"\\\\`\"" },
+        peg$c138 = function() { return '`' },
+        peg$c139 = /^[<>]/,
+        peg$c140 = { type: "class", value: "[<>]", description: "[<>]" },
+        peg$c141 = function(rw, commands) {
           return {
             type: 'processSubstitution',
             readWrite: rw,
             commands: commands,
           }
         },
-        peg$c133 = "<&",
-        peg$c134 = { type: "literal", value: "<&", description: "\"<&\"" },
-        peg$c135 = ">&",
-        peg$c136 = { type: "literal", value: ">&", description: "\">&\"" },
-        peg$c137 = function(fd, op, dest) {
+        peg$c142 = "<&",
+        peg$c143 = { type: "literal", value: "<&", description: "\"<&\"" },
+        peg$c144 = ">&",
+        peg$c145 = { type: "literal", value: ">&", description: "\">&\"" },
+        peg$c146 = function(fd, op, dest) {
           if (fd == null) fd = op[0] == '<' ? 0 : 1;
           return {
             type: 'moveFd',
@@ -336,7 +355,7 @@ var parser=(function() {
             dest: dest
           }
         },
-        peg$c138 = function(src, op, dest) {
+        peg$c147 = function(src, op, dest) {
           if (src == null) src = op[0] == '<' ? 0 : 1;
           return {
             type: 'duplicateFd',
@@ -345,7 +364,7 @@ var parser=(function() {
             destFd: dest,
           }
         },
-        peg$c139 = function(fd, op, filename) {
+        peg$c148 = function(fd, op, filename) {
           if (fd == null) fd = op[0] == '<' ? 0 : 1;
           return {
             type: 'redirectFd',
@@ -354,41 +373,229 @@ var parser=(function() {
             filename: filename
           }
         },
-        peg$c140 = ">|",
-        peg$c141 = { type: "literal", value: ">|", description: "\">|\"" },
-        peg$c142 = ">>",
-        peg$c143 = { type: "literal", value: ">>", description: "\">>\"" },
-        peg$c144 = "&>>",
-        peg$c145 = { type: "literal", value: "&>>", description: "\"&>>\"" },
-        peg$c146 = "&>",
-        peg$c147 = { type: "literal", value: "&>", description: "\"&>\"" },
-        peg$c148 = "<",
-        peg$c149 = { type: "literal", value: "<", description: "\"<\"" },
-        peg$c150 = ">",
-        peg$c151 = { type: "literal", value: ">", description: "\">\"" },
-        peg$c152 = /^[0-9]/,
-        peg$c153 = { type: "class", value: "[0-9]", description: "[0-9]" },
-        peg$c154 = function(digits) { return parseInt(join(digits), 10) },
-        peg$c155 = "&",
-        peg$c156 = { type: "literal", value: "&", description: "\"&\"" },
-        peg$c157 = function(op) {
+        peg$c149 = ">|",
+        peg$c150 = { type: "literal", value: ">|", description: "\">|\"" },
+        peg$c151 = ">>",
+        peg$c152 = { type: "literal", value: ">>", description: "\">>\"" },
+        peg$c153 = "&>>",
+        peg$c154 = { type: "literal", value: "&>>", description: "\"&>>\"" },
+        peg$c155 = "&>",
+        peg$c156 = { type: "literal", value: "&>", description: "\"&>\"" },
+        peg$c157 = "<",
+        peg$c158 = { type: "literal", value: "<", description: "\"<\"" },
+        peg$c159 = ">",
+        peg$c160 = { type: "literal", value: ">", description: "\">\"" },
+        peg$c161 = /^[0-9]/,
+        peg$c162 = { type: "class", value: "[0-9]", description: "[0-9]" },
+        peg$c163 = function(digits) { return parseInt(join(digits), 10) },
+        peg$c164 = "&",
+        peg$c165 = { type: "literal", value: "&", description: "\"&\"" },
+        peg$c166 = function(op) {
           return op == '\n' ? ';' : op
         },
-        peg$c158 = "|",
-        peg$c159 = { type: "literal", value: "|", description: "\"|\"" },
-        peg$c160 = function(command) {
+        peg$c167 = "|",
+        peg$c168 = { type: "literal", value: "|", description: "\"|\"" },
+        peg$c169 = function(command) {
           return {type: 'pipe', command: command}
         },
-        peg$c161 = { type: "other", description: "whitespace" },
-        peg$c162 = " ",
-        peg$c163 = { type: "literal", value: " ", description: "\" \"" },
-        peg$c164 = "\t",
-        peg$c165 = { type: "literal", value: "\t", description: "\"\\t\"" },
-        peg$c166 = { type: "other", description: "a comment" },
-        peg$c167 = "case",
-        peg$c168 = { type: "literal", value: "case", description: "\"case\"" },
-        peg$c169 = "esac",
-        peg$c170 = { type: "literal", value: "esac", description: "\"esac\"" },
+        peg$c170 = { type: "other", description: "whitespace" },
+        peg$c171 = " ",
+        peg$c172 = { type: "literal", value: " ", description: "\" \"" },
+        peg$c173 = "\t",
+        peg$c174 = { type: "literal", value: "\t", description: "\"\\t\"" },
+        peg$c175 = { type: "other", description: "a comment" },
+        peg$c176 = "case",
+        peg$c177 = { type: "literal", value: "case", description: "\"case\"" },
+        peg$c178 = "esac",
+        peg$c179 = { type: "literal", value: "esac", description: "\"esac\"" },
+        peg$c180 = { type: "other", description: "an arithmetic expression" },
+        peg$c181 = function(expression) { return expression },
+        peg$c182 = { type: "other", description: "a sequence of arithmetic expressions" },
+        peg$c183 = ",",
+        peg$c184 = { type: "literal", value: ",", description: "\",\"" },
+        peg$c185 = function(head, expr) { return expr },
+        peg$c186 = function(head, tail) {
+          if (tail.length) {
+            return {
+              type: 'arithmeticSequence',
+              expressions: [head].concat(tail)
+            }
+          }
+          return head
+        },
+        peg$c187 = { type: "other", description: "an arithmetic assignment" },
+        peg$c188 = "*=",
+        peg$c189 = { type: "literal", value: "*=", description: "\"*=\"" },
+        peg$c190 = "/=",
+        peg$c191 = { type: "literal", value: "/=", description: "\"/=\"" },
+        peg$c192 = "%=",
+        peg$c193 = { type: "literal", value: "%=", description: "\"%=\"" },
+        peg$c194 = "+=",
+        peg$c195 = { type: "literal", value: "+=", description: "\"+=\"" },
+        peg$c196 = "-=",
+        peg$c197 = { type: "literal", value: "-=", description: "\"-=\"" },
+        peg$c198 = "<<=",
+        peg$c199 = { type: "literal", value: "<<=", description: "\"<<=\"" },
+        peg$c200 = ">>=",
+        peg$c201 = { type: "literal", value: ">>=", description: "\">>=\"" },
+        peg$c202 = "&=",
+        peg$c203 = { type: "literal", value: "&=", description: "\"&=\"" },
+        peg$c204 = "^=",
+        peg$c205 = { type: "literal", value: "^=", description: "\"^=\"" },
+        peg$c206 = "|=",
+        peg$c207 = { type: "literal", value: "|=", description: "\"|=\"" },
+        peg$c208 = function(left, operator, right) {
+            return {
+              type: 'arithmeticAssignment',
+              left: left,
+              operator: operator,
+              right: right
+            }
+          },
+        peg$c209 = function(other) { return other },
+        peg$c210 = { type: "other", description: "an arithmetic conditional expression" },
+        peg$c211 = ":",
+        peg$c212 = { type: "literal", value: ":", description: "\":\"" },
+        peg$c213 = function(test, consequent, alternate) {
+            return {
+              type: 'arithmeticConditional',
+              test: test,
+              consequent: consequent,
+              alternate: alternate
+            }
+          },
+        peg$c214 = { type: "other", description: "an arithmetic logical or" },
+        peg$c215 = function(head, op, node) { return {op: op, node: node} },
+        peg$c216 = function(head, tail) {
+          return buildTree(head, tail, function (child, current) {
+            return {
+              type: 'arithmeticLogical',
+              operator: current.op,
+              left: child,
+              right: current.node
+            }
+          });
+        },
+        peg$c217 = { type: "other", description: "an arithmetic logical and" },
+        peg$c218 = /^[|=]/,
+        peg$c219 = { type: "class", value: "[|=]", description: "[|=]" },
+        peg$c220 = function(head, tail) {
+          return buildTree(head, tail, function (child, current) {
+            return {
+              type: 'arithmeticBinary',
+              operator: current.op,
+              left: child,
+              right: current.node
+            }
+          });
+        },
+        peg$c221 = "^",
+        peg$c222 = { type: "literal", value: "^", description: "\"^\"" },
+        peg$c223 = /^[&=]/,
+        peg$c224 = { type: "class", value: "[&=]", description: "[&=]" },
+        peg$c225 = "==",
+        peg$c226 = { type: "literal", value: "==", description: "\"==\"" },
+        peg$c227 = "!=",
+        peg$c228 = { type: "literal", value: "!=", description: "\"!=\"" },
+        peg$c229 = "<=",
+        peg$c230 = { type: "literal", value: "<=", description: "\"<=\"" },
+        peg$c231 = ">=",
+        peg$c232 = { type: "literal", value: ">=", description: "\">=\"" },
+        peg$c233 = function(head, v) { return v },
+        peg$c234 = "<<",
+        peg$c235 = { type: "literal", value: "<<", description: "\"<<\"" },
+        peg$c236 = "+",
+        peg$c237 = { type: "literal", value: "+", description: "\"+\"" },
+        peg$c238 = "/",
+        peg$c239 = { type: "literal", value: "/", description: "\"/\"" },
+        peg$c240 = "%",
+        peg$c241 = { type: "literal", value: "%", description: "\"%\"" },
+        peg$c242 = "**",
+        peg$c243 = { type: "literal", value: "**", description: "\"**\"" },
+        peg$c244 = "!",
+        peg$c245 = { type: "literal", value: "!", description: "\"!\"" },
+        peg$c246 = "~",
+        peg$c247 = { type: "literal", value: "~", description: "\"~\"" },
+        peg$c248 = function(operator, argument) {
+            return {
+              type: 'arithmeticUnary',
+              operator: operator,
+              argument: argument
+            }
+          },
+        peg$c249 = /^[+=]/,
+        peg$c250 = { type: "class", value: "[+=]", description: "[+=]" },
+        peg$c251 = function(op) { return op },
+        peg$c252 = /^[\-=]/,
+        peg$c253 = { type: "class", value: "[-=]", description: "[-=]" },
+        peg$c254 = "++",
+        peg$c255 = { type: "literal", value: "++", description: "\"++\"" },
+        peg$c256 = "--",
+        peg$c257 = { type: "literal", value: "--", description: "\"--\"" },
+        peg$c258 = function(operator, argument) {
+            return {
+              type: 'arithmeticUpdate',
+              operator: operator,
+              argument: argument,
+              prefix: true
+            }
+          },
+        peg$c259 = function(argument, op) { return op },
+        peg$c260 = function(argument, operators) {
+            return buildTree(argument, operators, function (node, operator) {
+              return {
+                type: 'arithmeticUpdate',
+                operator: operator,
+                argument: node,
+                prefix: false
+              }
+            });
+          },
+        peg$c261 = function(head, property) { return property },
+        peg$c262 = function(head, tail) {
+          return buildTree(head, tail, function (child, current) {
+            return {
+              type: 'arithmeticMemberExpression',
+              array: child,
+              property: current
+            }
+          });
+        },
+        peg$c263 = function(value) { return value },
+        peg$c264 = { type: "other", description: "arithmetic variable" },
+        peg$c265 = function(name) {
+          // TODO: check if array
+          return {type: 'variable', name: name.join('')}
+        },
+        peg$c266 = /^[$"';&<>\n()[\]*?|`:+\^\- ]/,
+        peg$c267 = { type: "class", value: "[$\"';&<>\\n()\\[\\]*?|`:+^\\- ]", description: "[$\"';&<>\\n()\\[\\]*?|`:+^\\- ]" },
+        peg$c268 = function(pieces) {
+          // TODO: if it's an array, nest it
+          return flattenConcatenation(pieces)
+        },
+        peg$c269 = function(val) { return val },
+        peg$c270 = "0",
+        peg$c271 = { type: "literal", value: "0", description: "\"0\"" },
+        peg$c272 = /^[xX]/,
+        peg$c273 = { type: "class", value: "[xX]", description: "[xX]" },
+        peg$c274 = /^[0-9a-fA-Z]/,
+        peg$c275 = { type: "class", value: "[0-9a-fA-Z]", description: "[0-9a-fA-Z]" },
+        peg$c276 = function(digits) {
+            return {type: 'number', value: parseInt(digits.join(''), 16)}
+          },
+        peg$c277 = /^[0-9a-zA-Z]/,
+        peg$c278 = { type: "class", value: "[0-9a-zA-Z]", description: "[0-9a-zA-Z]" },
+        peg$c279 = function(base, digits) {
+            return {type: 'number', value: parseInt(digits.join(''), parseInt(base.join(''), 10))}
+          },
+        peg$c280 = /^[0-7]/,
+        peg$c281 = { type: "class", value: "[0-7]", description: "[0-7]" },
+        peg$c282 = function(digits) {
+            return {type: 'number', value: parseInt(digits.join(''), 8)}
+          },
+        peg$c283 = function(digits) {
+            return {type: 'number', value: parseInt(digits.join(''), 10)}
+          },
 
         peg$currPos          = 0,
         peg$savedPos         = 0,
@@ -719,19 +926,22 @@ var parser=(function() {
       var s0, s1, s2, s3, s4;
 
       s0 = peg$currPos;
-      s1 = peg$parsesubshell();
+      s1 = peg$parsearithmeticStatement();
       if (s1 === peg$FAILED) {
-        s1 = peg$parsebashExtensions();
+        s1 = peg$parsesubshell();
         if (s1 === peg$FAILED) {
-          s1 = peg$parsecommand();
+          s1 = peg$parsebashExtensions();
           if (s1 === peg$FAILED) {
-            s1 = peg$parsevariableAssignment();
+            s1 = peg$parsecommand();
             if (s1 === peg$FAILED) {
-              s1 = peg$parseifBlock();
+              s1 = peg$parsevariableAssignment();
               if (s1 === peg$FAILED) {
-                s1 = peg$parseconditionalLoop();
+                s1 = peg$parseifBlock();
                 if (s1 === peg$FAILED) {
-                  s1 = peg$parseforLoop();
+                  s1 = peg$parseconditionalLoop();
+                  if (s1 === peg$FAILED) {
+                    s1 = peg$parseforLoop();
+                  }
                 }
               }
             }
@@ -827,14 +1037,14 @@ var parser=(function() {
       return s0;
     }
 
-    function peg$parsesubshell() {
+    function peg$parsearithmeticStatement() {
       var s0, s1, s2, s3, s4, s5;
 
       peg$silentFails++;
       s0 = peg$currPos;
-      if (input.charCodeAt(peg$currPos) === 40) {
+      if (input.substr(peg$currPos, 2) === peg$c9) {
         s1 = peg$c9;
-        peg$currPos++;
+        peg$currPos += 2;
       } else {
         s1 = peg$FAILED;
         if (peg$silentFails === 0) { peg$fail(peg$c10); }
@@ -847,7 +1057,7 @@ var parser=(function() {
           s3 = peg$parsespace();
         }
         if (s2 !== peg$FAILED) {
-          s3 = peg$parsestatementList();
+          s3 = peg$parsearithmetic();
           if (s3 !== peg$FAILED) {
             s4 = [];
             s5 = peg$parsespace();
@@ -856,9 +1066,9 @@ var parser=(function() {
               s5 = peg$parsespace();
             }
             if (s4 !== peg$FAILED) {
-              if (input.charCodeAt(peg$currPos) === 41) {
+              if (input.substr(peg$currPos, 2) === peg$c11) {
                 s5 = peg$c11;
-                peg$currPos++;
+                peg$currPos += 2;
               } else {
                 s5 = peg$FAILED;
                 if (peg$silentFails === 0) { peg$fail(peg$c12); }
@@ -896,6 +1106,75 @@ var parser=(function() {
       return s0;
     }
 
+    function peg$parsesubshell() {
+      var s0, s1, s2, s3, s4, s5;
+
+      peg$silentFails++;
+      s0 = peg$currPos;
+      if (input.charCodeAt(peg$currPos) === 40) {
+        s1 = peg$c15;
+        peg$currPos++;
+      } else {
+        s1 = peg$FAILED;
+        if (peg$silentFails === 0) { peg$fail(peg$c16); }
+      }
+      if (s1 !== peg$FAILED) {
+        s2 = [];
+        s3 = peg$parsespace();
+        while (s3 !== peg$FAILED) {
+          s2.push(s3);
+          s3 = peg$parsespace();
+        }
+        if (s2 !== peg$FAILED) {
+          s3 = peg$parsestatementList();
+          if (s3 !== peg$FAILED) {
+            s4 = [];
+            s5 = peg$parsespace();
+            while (s5 !== peg$FAILED) {
+              s4.push(s5);
+              s5 = peg$parsespace();
+            }
+            if (s4 !== peg$FAILED) {
+              if (input.charCodeAt(peg$currPos) === 41) {
+                s5 = peg$c17;
+                peg$currPos++;
+              } else {
+                s5 = peg$FAILED;
+                if (peg$silentFails === 0) { peg$fail(peg$c18); }
+              }
+              if (s5 !== peg$FAILED) {
+                peg$savedPos = s0;
+                s1 = peg$c19(s3);
+                s0 = s1;
+              } else {
+                peg$currPos = s0;
+                s0 = peg$FAILED;
+              }
+            } else {
+              peg$currPos = s0;
+              s0 = peg$FAILED;
+            }
+          } else {
+            peg$currPos = s0;
+            s0 = peg$FAILED;
+          }
+        } else {
+          peg$currPos = s0;
+          s0 = peg$FAILED;
+        }
+      } else {
+        peg$currPos = s0;
+        s0 = peg$FAILED;
+      }
+      peg$silentFails--;
+      if (s0 === peg$FAILED) {
+        s1 = peg$FAILED;
+        if (peg$silentFails === 0) { peg$fail(peg$c14); }
+      }
+
+      return s0;
+    }
+
     function peg$parsecommand() {
       var s0, s1, s2, s3, s4, s5, s6;
 
@@ -1049,7 +1328,7 @@ var parser=(function() {
             }
             if (s4 !== peg$FAILED) {
               peg$savedPos = s0;
-              s1 = peg$c15(s1, s2, s3, s4);
+              s1 = peg$c21(s1, s2, s3, s4);
               s0 = s1;
             } else {
               peg$currPos = s0;
@@ -1070,7 +1349,7 @@ var parser=(function() {
       peg$silentFails--;
       if (s0 === peg$FAILED) {
         s1 = peg$FAILED;
-        if (peg$silentFails === 0) { peg$fail(peg$c14); }
+        if (peg$silentFails === 0) { peg$fail(peg$c20); }
       }
 
       return s0;
@@ -1083,7 +1362,7 @@ var parser=(function() {
       s1 = peg$parsescript();
       if (s1 !== peg$FAILED) {
         peg$savedPos = s0;
-        s1 = peg$c16(s1);
+        s1 = peg$c22(s1);
       }
       s0 = s1;
 
@@ -1095,12 +1374,12 @@ var parser=(function() {
 
       peg$silentFails++;
       s0 = peg$currPos;
-      if (input.substr(peg$currPos, 2) === peg$c18) {
-        s1 = peg$c18;
+      if (input.substr(peg$currPos, 2) === peg$c24) {
+        s1 = peg$c24;
         peg$currPos += 2;
       } else {
         s1 = peg$FAILED;
-        if (peg$silentFails === 0) { peg$fail(peg$c19); }
+        if (peg$silentFails === 0) { peg$fail(peg$c25); }
       }
       if (s1 !== peg$FAILED) {
         s2 = [];
@@ -1116,12 +1395,12 @@ var parser=(function() {
         if (s2 !== peg$FAILED) {
           s3 = peg$parsecondition();
           if (s3 !== peg$FAILED) {
-            if (input.substr(peg$currPos, 4) === peg$c20) {
-              s4 = peg$c20;
+            if (input.substr(peg$currPos, 4) === peg$c26) {
+              s4 = peg$c26;
               peg$currPos += 4;
             } else {
               s4 = peg$FAILED;
-              if (peg$silentFails === 0) { peg$fail(peg$c21); }
+              if (peg$silentFails === 0) { peg$fail(peg$c27); }
             }
             if (s4 !== peg$FAILED) {
               s5 = [];
@@ -1145,12 +1424,12 @@ var parser=(function() {
                   }
                   if (s7 !== peg$FAILED) {
                     s8 = peg$currPos;
-                    if (input.substr(peg$currPos, 4) === peg$c22) {
-                      s9 = peg$c22;
+                    if (input.substr(peg$currPos, 4) === peg$c28) {
+                      s9 = peg$c28;
                       peg$currPos += 4;
                     } else {
                       s9 = peg$FAILED;
-                      if (peg$silentFails === 0) { peg$fail(peg$c23); }
+                      if (peg$silentFails === 0) { peg$fail(peg$c29); }
                     }
                     if (s9 !== peg$FAILED) {
                       s10 = peg$parsescript();
@@ -1169,16 +1448,16 @@ var parser=(function() {
                       s8 = null;
                     }
                     if (s8 !== peg$FAILED) {
-                      if (input.substr(peg$currPos, 2) === peg$c24) {
-                        s9 = peg$c24;
+                      if (input.substr(peg$currPos, 2) === peg$c30) {
+                        s9 = peg$c30;
                         peg$currPos += 2;
                       } else {
                         s9 = peg$FAILED;
-                        if (peg$silentFails === 0) { peg$fail(peg$c25); }
+                        if (peg$silentFails === 0) { peg$fail(peg$c31); }
                       }
                       if (s9 !== peg$FAILED) {
                         peg$savedPos = s0;
-                        s1 = peg$c26(s3, s6, s7, s8);
+                        s1 = peg$c32(s3, s6, s7, s8);
                         s0 = s1;
                       } else {
                         peg$currPos = s0;
@@ -1219,7 +1498,7 @@ var parser=(function() {
       peg$silentFails--;
       if (s0 === peg$FAILED) {
         s1 = peg$FAILED;
-        if (peg$silentFails === 0) { peg$fail(peg$c17); }
+        if (peg$silentFails === 0) { peg$fail(peg$c23); }
       }
 
       return s0;
@@ -1229,12 +1508,12 @@ var parser=(function() {
       var s0, s1, s2, s3, s4, s5, s6;
 
       s0 = peg$currPos;
-      if (input.substr(peg$currPos, 4) === peg$c27) {
-        s1 = peg$c27;
+      if (input.substr(peg$currPos, 4) === peg$c33) {
+        s1 = peg$c33;
         peg$currPos += 4;
       } else {
         s1 = peg$FAILED;
-        if (peg$silentFails === 0) { peg$fail(peg$c28); }
+        if (peg$silentFails === 0) { peg$fail(peg$c34); }
       }
       if (s1 !== peg$FAILED) {
         s2 = [];
@@ -1250,12 +1529,12 @@ var parser=(function() {
         if (s2 !== peg$FAILED) {
           s3 = peg$parsecondition();
           if (s3 !== peg$FAILED) {
-            if (input.substr(peg$currPos, 4) === peg$c20) {
-              s4 = peg$c20;
+            if (input.substr(peg$currPos, 4) === peg$c26) {
+              s4 = peg$c26;
               peg$currPos += 4;
             } else {
               s4 = peg$FAILED;
-              if (peg$silentFails === 0) { peg$fail(peg$c21); }
+              if (peg$silentFails === 0) { peg$fail(peg$c27); }
             }
             if (s4 !== peg$FAILED) {
               s5 = [];
@@ -1272,7 +1551,7 @@ var parser=(function() {
                 s6 = peg$parsescript();
                 if (s6 !== peg$FAILED) {
                   peg$savedPos = s0;
-                  s1 = peg$c29(s3, s6);
+                  s1 = peg$c35(s3, s6);
                   s0 = s1;
                 } else {
                   peg$currPos = s0;
@@ -1307,20 +1586,20 @@ var parser=(function() {
 
       peg$silentFails++;
       s0 = peg$currPos;
-      if (input.substr(peg$currPos, 5) === peg$c31) {
-        s1 = peg$c31;
+      if (input.substr(peg$currPos, 5) === peg$c37) {
+        s1 = peg$c37;
         peg$currPos += 5;
       } else {
         s1 = peg$FAILED;
-        if (peg$silentFails === 0) { peg$fail(peg$c32); }
+        if (peg$silentFails === 0) { peg$fail(peg$c38); }
       }
       if (s1 === peg$FAILED) {
-        if (input.substr(peg$currPos, 5) === peg$c33) {
-          s1 = peg$c33;
+        if (input.substr(peg$currPos, 5) === peg$c39) {
+          s1 = peg$c39;
           peg$currPos += 5;
         } else {
           s1 = peg$FAILED;
-          if (peg$silentFails === 0) { peg$fail(peg$c34); }
+          if (peg$silentFails === 0) { peg$fail(peg$c40); }
         }
       }
       if (s1 !== peg$FAILED) {
@@ -1337,12 +1616,12 @@ var parser=(function() {
         if (s2 !== peg$FAILED) {
           s3 = peg$parsecondition();
           if (s3 !== peg$FAILED) {
-            if (input.substr(peg$currPos, 2) === peg$c35) {
-              s4 = peg$c35;
+            if (input.substr(peg$currPos, 2) === peg$c41) {
+              s4 = peg$c41;
               peg$currPos += 2;
             } else {
               s4 = peg$FAILED;
-              if (peg$silentFails === 0) { peg$fail(peg$c36); }
+              if (peg$silentFails === 0) { peg$fail(peg$c42); }
             }
             if (s4 !== peg$FAILED) {
               s5 = [];
@@ -1358,16 +1637,16 @@ var parser=(function() {
               if (s5 !== peg$FAILED) {
                 s6 = peg$parsescript();
                 if (s6 !== peg$FAILED) {
-                  if (input.substr(peg$currPos, 4) === peg$c37) {
-                    s7 = peg$c37;
+                  if (input.substr(peg$currPos, 4) === peg$c43) {
+                    s7 = peg$c43;
                     peg$currPos += 4;
                   } else {
                     s7 = peg$FAILED;
-                    if (peg$silentFails === 0) { peg$fail(peg$c38); }
+                    if (peg$silentFails === 0) { peg$fail(peg$c44); }
                   }
                   if (s7 !== peg$FAILED) {
                     peg$savedPos = s0;
-                    s1 = peg$c39(s1, s3, s6);
+                    s1 = peg$c45(s1, s3, s6);
                     s0 = s1;
                   } else {
                     peg$currPos = s0;
@@ -1400,7 +1679,7 @@ var parser=(function() {
       peg$silentFails--;
       if (s0 === peg$FAILED) {
         s1 = peg$FAILED;
-        if (peg$silentFails === 0) { peg$fail(peg$c30); }
+        if (peg$silentFails === 0) { peg$fail(peg$c36); }
       }
 
       return s0;
@@ -1411,12 +1690,12 @@ var parser=(function() {
 
       peg$silentFails++;
       s0 = peg$currPos;
-      if (input.substr(peg$currPos, 3) === peg$c41) {
-        s1 = peg$c41;
+      if (input.substr(peg$currPos, 3) === peg$c47) {
+        s1 = peg$c47;
         peg$currPos += 3;
       } else {
         s1 = peg$FAILED;
-        if (peg$silentFails === 0) { peg$fail(peg$c42); }
+        if (peg$silentFails === 0) { peg$fail(peg$c48); }
       }
       if (s1 !== peg$FAILED) {
         s2 = [];
@@ -1444,12 +1723,12 @@ var parser=(function() {
             }
             if (s4 !== peg$FAILED) {
               s5 = peg$currPos;
-              if (input.substr(peg$currPos, 2) === peg$c43) {
-                s6 = peg$c43;
+              if (input.substr(peg$currPos, 2) === peg$c49) {
+                s6 = peg$c49;
                 peg$currPos += 2;
               } else {
                 s6 = peg$FAILED;
-                if (peg$silentFails === 0) { peg$fail(peg$c44); }
+                if (peg$silentFails === 0) { peg$fail(peg$c50); }
               }
               if (s6 !== peg$FAILED) {
                 s7 = [];
@@ -1527,19 +1806,19 @@ var parser=(function() {
                 }
                 if (s6 !== peg$FAILED) {
                   if (input.charCodeAt(peg$currPos) === 59) {
-                    s7 = peg$c45;
+                    s7 = peg$c51;
                     peg$currPos++;
                   } else {
                     s7 = peg$FAILED;
-                    if (peg$silentFails === 0) { peg$fail(peg$c46); }
+                    if (peg$silentFails === 0) { peg$fail(peg$c52); }
                   }
                   if (s7 === peg$FAILED) {
                     if (input.charCodeAt(peg$currPos) === 10) {
-                      s7 = peg$c47;
+                      s7 = peg$c53;
                       peg$currPos++;
                     } else {
                       s7 = peg$FAILED;
-                      if (peg$silentFails === 0) { peg$fail(peg$c48); }
+                      if (peg$silentFails === 0) { peg$fail(peg$c54); }
                     }
                   }
                   if (s7 !== peg$FAILED) {
@@ -1550,12 +1829,12 @@ var parser=(function() {
                       s9 = peg$parsespaceNL();
                     }
                     if (s8 !== peg$FAILED) {
-                      if (input.substr(peg$currPos, 2) === peg$c35) {
-                        s9 = peg$c35;
+                      if (input.substr(peg$currPos, 2) === peg$c41) {
+                        s9 = peg$c41;
                         peg$currPos += 2;
                       } else {
                         s9 = peg$FAILED;
-                        if (peg$silentFails === 0) { peg$fail(peg$c36); }
+                        if (peg$silentFails === 0) { peg$fail(peg$c42); }
                       }
                       if (s9 !== peg$FAILED) {
                         s10 = [];
@@ -1578,16 +1857,16 @@ var parser=(function() {
                               s13 = peg$parsespaceNL();
                             }
                             if (s12 !== peg$FAILED) {
-                              if (input.substr(peg$currPos, 4) === peg$c37) {
-                                s13 = peg$c37;
+                              if (input.substr(peg$currPos, 4) === peg$c43) {
+                                s13 = peg$c43;
                                 peg$currPos += 4;
                               } else {
                                 s13 = peg$FAILED;
-                                if (peg$silentFails === 0) { peg$fail(peg$c38); }
+                                if (peg$silentFails === 0) { peg$fail(peg$c44); }
                               }
                               if (s13 !== peg$FAILED) {
                                 peg$savedPos = s0;
-                                s1 = peg$c49(s3, s5, s11);
+                                s1 = peg$c55(s3, s5, s11);
                                 s0 = s1;
                               } else {
                                 peg$currPos = s0;
@@ -1644,7 +1923,7 @@ var parser=(function() {
       peg$silentFails--;
       if (s0 === peg$FAILED) {
         s1 = peg$FAILED;
-        if (peg$silentFails === 0) { peg$fail(peg$c40); }
+        if (peg$silentFails === 0) { peg$fail(peg$c46); }
       }
 
       return s0;
@@ -1666,12 +1945,12 @@ var parser=(function() {
 
       peg$silentFails++;
       s0 = peg$currPos;
-      if (input.substr(peg$currPos, 4) === peg$c51) {
-        s1 = peg$c51;
+      if (input.substr(peg$currPos, 4) === peg$c57) {
+        s1 = peg$c57;
         peg$currPos += 4;
       } else {
         s1 = peg$FAILED;
-        if (peg$silentFails === 0) { peg$fail(peg$c52); }
+        if (peg$silentFails === 0) { peg$fail(peg$c58); }
       }
       if (s1 !== peg$FAILED) {
         s2 = [];
@@ -1688,30 +1967,30 @@ var parser=(function() {
           s3 = [];
           s4 = peg$currPos;
           if (input.charCodeAt(peg$currPos) === 45) {
-            s5 = peg$c53;
+            s5 = peg$c59;
             peg$currPos++;
           } else {
             s5 = peg$FAILED;
-            if (peg$silentFails === 0) { peg$fail(peg$c54); }
+            if (peg$silentFails === 0) { peg$fail(peg$c60); }
           }
           if (s5 !== peg$FAILED) {
             s6 = [];
-            if (peg$c55.test(input.charAt(peg$currPos))) {
+            if (peg$c61.test(input.charAt(peg$currPos))) {
               s7 = input.charAt(peg$currPos);
               peg$currPos++;
             } else {
               s7 = peg$FAILED;
-              if (peg$silentFails === 0) { peg$fail(peg$c56); }
+              if (peg$silentFails === 0) { peg$fail(peg$c62); }
             }
             if (s7 !== peg$FAILED) {
               while (s7 !== peg$FAILED) {
                 s6.push(s7);
-                if (peg$c55.test(input.charAt(peg$currPos))) {
+                if (peg$c61.test(input.charAt(peg$currPos))) {
                   s7 = input.charAt(peg$currPos);
                   peg$currPos++;
                 } else {
                   s7 = peg$FAILED;
-                  if (peg$silentFails === 0) { peg$fail(peg$c56); }
+                  if (peg$silentFails === 0) { peg$fail(peg$c62); }
                 }
               }
             } else {
@@ -1747,30 +2026,30 @@ var parser=(function() {
             s3.push(s4);
             s4 = peg$currPos;
             if (input.charCodeAt(peg$currPos) === 45) {
-              s5 = peg$c53;
+              s5 = peg$c59;
               peg$currPos++;
             } else {
               s5 = peg$FAILED;
-              if (peg$silentFails === 0) { peg$fail(peg$c54); }
+              if (peg$silentFails === 0) { peg$fail(peg$c60); }
             }
             if (s5 !== peg$FAILED) {
               s6 = [];
-              if (peg$c55.test(input.charAt(peg$currPos))) {
+              if (peg$c61.test(input.charAt(peg$currPos))) {
                 s7 = input.charAt(peg$currPos);
                 peg$currPos++;
               } else {
                 s7 = peg$FAILED;
-                if (peg$silentFails === 0) { peg$fail(peg$c56); }
+                if (peg$silentFails === 0) { peg$fail(peg$c62); }
               }
               if (s7 !== peg$FAILED) {
                 while (s7 !== peg$FAILED) {
                   s6.push(s7);
-                  if (peg$c55.test(input.charAt(peg$currPos))) {
+                  if (peg$c61.test(input.charAt(peg$currPos))) {
                     s7 = input.charAt(peg$currPos);
                     peg$currPos++;
                   } else {
                     s7 = peg$FAILED;
-                    if (peg$silentFails === 0) { peg$fail(peg$c56); }
+                    if (peg$silentFails === 0) { peg$fail(peg$c62); }
                   }
                 }
               } else {
@@ -1807,7 +2086,7 @@ var parser=(function() {
             s4 = peg$parsestatementList();
             if (s4 !== peg$FAILED) {
               peg$savedPos = s0;
-              s1 = peg$c57(s3, s4);
+              s1 = peg$c63(s3, s4);
               s0 = s1;
             } else {
               peg$currPos = s0;
@@ -1828,7 +2107,7 @@ var parser=(function() {
       peg$silentFails--;
       if (s0 === peg$FAILED) {
         s1 = peg$FAILED;
-        if (peg$silentFails === 0) { peg$fail(peg$c50); }
+        if (peg$silentFails === 0) { peg$fail(peg$c56); }
       }
 
       return s0;
@@ -1839,40 +2118,40 @@ var parser=(function() {
 
       peg$silentFails++;
       s0 = peg$currPos;
-      if (input.substr(peg$currPos, 7) === peg$c59) {
-        s1 = peg$c59;
+      if (input.substr(peg$currPos, 7) === peg$c65) {
+        s1 = peg$c65;
         peg$currPos += 7;
       } else {
         s1 = peg$FAILED;
-        if (peg$silentFails === 0) { peg$fail(peg$c60); }
+        if (peg$silentFails === 0) { peg$fail(peg$c66); }
       }
       if (s1 === peg$FAILED) {
-        if (input.substr(peg$currPos, 7) === peg$c61) {
-          s1 = peg$c61;
+        if (input.substr(peg$currPos, 7) === peg$c67) {
+          s1 = peg$c67;
           peg$currPos += 7;
         } else {
           s1 = peg$FAILED;
-          if (peg$silentFails === 0) { peg$fail(peg$c62); }
+          if (peg$silentFails === 0) { peg$fail(peg$c68); }
         }
       }
       if (s1 !== peg$FAILED) {
         s2 = [];
-        if (peg$c63.test(input.charAt(peg$currPos))) {
+        if (peg$c69.test(input.charAt(peg$currPos))) {
           s3 = input.charAt(peg$currPos);
           peg$currPos++;
         } else {
           s3 = peg$FAILED;
-          if (peg$silentFails === 0) { peg$fail(peg$c64); }
+          if (peg$silentFails === 0) { peg$fail(peg$c70); }
         }
         if (s3 !== peg$FAILED) {
           while (s3 !== peg$FAILED) {
             s2.push(s3);
-            if (peg$c63.test(input.charAt(peg$currPos))) {
+            if (peg$c69.test(input.charAt(peg$currPos))) {
               s3 = input.charAt(peg$currPos);
               peg$currPos++;
             } else {
               s3 = peg$FAILED;
-              if (peg$silentFails === 0) { peg$fail(peg$c64); }
+              if (peg$silentFails === 0) { peg$fail(peg$c70); }
             }
           }
         } else {
@@ -1880,19 +2159,19 @@ var parser=(function() {
         }
         if (s2 !== peg$FAILED) {
           if (input.charCodeAt(peg$currPos) === 59) {
-            s3 = peg$c45;
+            s3 = peg$c51;
             peg$currPos++;
           } else {
             s3 = peg$FAILED;
-            if (peg$silentFails === 0) { peg$fail(peg$c46); }
+            if (peg$silentFails === 0) { peg$fail(peg$c52); }
           }
           if (s3 === peg$FAILED) {
             if (input.charCodeAt(peg$currPos) === 10) {
-              s3 = peg$c47;
+              s3 = peg$c53;
               peg$currPos++;
             } else {
               s3 = peg$FAILED;
-              if (peg$silentFails === 0) { peg$fail(peg$c48); }
+              if (peg$silentFails === 0) { peg$fail(peg$c54); }
             }
           }
           if (s3 !== peg$FAILED) {
@@ -1913,7 +2192,7 @@ var parser=(function() {
       peg$silentFails--;
       if (s0 === peg$FAILED) {
         s1 = peg$FAILED;
-        if (peg$silentFails === 0) { peg$fail(peg$c58); }
+        if (peg$silentFails === 0) { peg$fail(peg$c64); }
       }
 
       return s0;
@@ -1927,11 +2206,11 @@ var parser=(function() {
       s1 = peg$parsewritableVariableName();
       if (s1 !== peg$FAILED) {
         if (input.charCodeAt(peg$currPos) === 61) {
-          s2 = peg$c66;
+          s2 = peg$c72;
           peg$currPos++;
         } else {
           s2 = peg$FAILED;
-          if (peg$silentFails === 0) { peg$fail(peg$c67); }
+          if (peg$silentFails === 0) { peg$fail(peg$c73); }
         }
         if (s2 !== peg$FAILED) {
           s3 = peg$parseargument();
@@ -1940,7 +2219,7 @@ var parser=(function() {
           }
           if (s3 !== peg$FAILED) {
             peg$savedPos = s0;
-            s1 = peg$c68(s1, s3);
+            s1 = peg$c74(s1, s3);
             s0 = s1;
           } else {
             peg$currPos = s0;
@@ -1957,7 +2236,7 @@ var parser=(function() {
       peg$silentFails--;
       if (s0 === peg$FAILED) {
         s1 = peg$FAILED;
-        if (peg$silentFails === 0) { peg$fail(peg$c65); }
+        if (peg$silentFails === 0) { peg$fail(peg$c71); }
       }
 
       return s0;
@@ -2007,7 +2286,7 @@ var parser=(function() {
             }
             if (s4 !== peg$FAILED) {
               peg$savedPos = s0;
-              s1 = peg$c70(s4);
+              s1 = peg$c76(s4);
               s0 = s1;
             } else {
               peg$currPos = s0;
@@ -2028,7 +2307,7 @@ var parser=(function() {
       peg$silentFails--;
       if (s0 === peg$FAILED) {
         s1 = peg$FAILED;
-        if (peg$silentFails === 0) { peg$fail(peg$c69); }
+        if (peg$silentFails === 0) { peg$fail(peg$c75); }
       }
 
       return s0;
@@ -2037,20 +2316,20 @@ var parser=(function() {
     function peg$parsebuiltinCommandName() {
       var s0;
 
-      if (input.substr(peg$currPos, 2) === peg$c71) {
-        s0 = peg$c71;
+      if (input.substr(peg$currPos, 2) === peg$c77) {
+        s0 = peg$c77;
         peg$currPos += 2;
       } else {
         s0 = peg$FAILED;
-        if (peg$silentFails === 0) { peg$fail(peg$c72); }
+        if (peg$silentFails === 0) { peg$fail(peg$c78); }
       }
       if (s0 === peg$FAILED) {
         if (input.charCodeAt(peg$currPos) === 91) {
-          s0 = peg$c73;
+          s0 = peg$c79;
           peg$currPos++;
         } else {
           s0 = peg$FAILED;
-          if (peg$silentFails === 0) { peg$fail(peg$c74); }
+          if (peg$silentFails === 0) { peg$fail(peg$c80); }
         }
       }
 
@@ -2068,7 +2347,7 @@ var parser=(function() {
       peg$silentFails--;
       if (s0 === peg$FAILED) {
         s1 = peg$FAILED;
-        if (peg$silentFails === 0) { peg$fail(peg$c75); }
+        if (peg$silentFails === 0) { peg$fail(peg$c81); }
       }
 
       return s0;
@@ -2088,11 +2367,14 @@ var parser=(function() {
           if (s2 === peg$FAILED) {
             s2 = peg$parsevariableSubstitution();
             if (s2 === peg$FAILED) {
-              s2 = peg$parsecommandSubstitution();
+              s2 = peg$parsearithmeticSubstitution();
               if (s2 === peg$FAILED) {
-                s2 = peg$parsesingleQuote();
+                s2 = peg$parsecommandSubstitution();
                 if (s2 === peg$FAILED) {
-                  s2 = peg$parsedoubleQuote();
+                  s2 = peg$parsesingleQuote();
+                  if (s2 === peg$FAILED) {
+                    s2 = peg$parsedoubleQuote();
+                  }
                 }
               }
             }
@@ -2110,11 +2392,14 @@ var parser=(function() {
               if (s2 === peg$FAILED) {
                 s2 = peg$parsevariableSubstitution();
                 if (s2 === peg$FAILED) {
-                  s2 = peg$parsecommandSubstitution();
+                  s2 = peg$parsearithmeticSubstitution();
                   if (s2 === peg$FAILED) {
-                    s2 = peg$parsesingleQuote();
+                    s2 = peg$parsecommandSubstitution();
                     if (s2 === peg$FAILED) {
-                      s2 = peg$parsedoubleQuote();
+                      s2 = peg$parsesingleQuote();
+                      if (s2 === peg$FAILED) {
+                        s2 = peg$parsedoubleQuote();
+                      }
                     }
                   }
                 }
@@ -2127,13 +2412,13 @@ var parser=(function() {
       }
       if (s1 !== peg$FAILED) {
         peg$savedPos = s0;
-        s1 = peg$c77(s1);
+        s1 = peg$c83(s1);
       }
       s0 = s1;
       peg$silentFails--;
       if (s0 === peg$FAILED) {
         s1 = peg$FAILED;
-        if (peg$silentFails === 0) { peg$fail(peg$c76); }
+        if (peg$silentFails === 0) { peg$fail(peg$c82); }
       }
 
       return s0;
@@ -2147,11 +2432,11 @@ var parser=(function() {
       s1 = peg$currPos;
       peg$silentFails++;
       if (input.charCodeAt(peg$currPos) === 35) {
-        s2 = peg$c79;
+        s2 = peg$c85;
         peg$currPos++;
       } else {
         s2 = peg$FAILED;
-        if (peg$silentFails === 0) { peg$fail(peg$c80); }
+        if (peg$silentFails === 0) { peg$fail(peg$c86); }
       }
       peg$silentFails--;
       if (s2 === peg$FAILED) {
@@ -2173,7 +2458,7 @@ var parser=(function() {
         }
         if (s2 !== peg$FAILED) {
           peg$savedPos = s0;
-          s1 = peg$c81(s2);
+          s1 = peg$c87(s2);
           s0 = s1;
         } else {
           peg$currPos = s0;
@@ -2186,7 +2471,7 @@ var parser=(function() {
       peg$silentFails--;
       if (s0 === peg$FAILED) {
         s1 = peg$FAILED;
-        if (peg$silentFails === 0) { peg$fail(peg$c78); }
+        if (peg$silentFails === 0) { peg$fail(peg$c84); }
       }
 
       return s0;
@@ -2197,17 +2482,17 @@ var parser=(function() {
 
       s0 = peg$currPos;
       if (input.charCodeAt(peg$currPos) === 92) {
-        s1 = peg$c82;
+        s1 = peg$c88;
         peg$currPos++;
       } else {
         s1 = peg$FAILED;
-        if (peg$silentFails === 0) { peg$fail(peg$c83); }
+        if (peg$silentFails === 0) { peg$fail(peg$c89); }
       }
       if (s1 !== peg$FAILED) {
         s2 = peg$parsebarewordMeta();
         if (s2 !== peg$FAILED) {
           peg$savedPos = s0;
-          s1 = peg$c84(s2);
+          s1 = peg$c90(s2);
           s0 = s1;
         } else {
           peg$currPos = s0;
@@ -2235,11 +2520,11 @@ var parser=(function() {
             peg$currPos++;
           } else {
             s2 = peg$FAILED;
-            if (peg$silentFails === 0) { peg$fail(peg$c85); }
+            if (peg$silentFails === 0) { peg$fail(peg$c91); }
           }
           if (s2 !== peg$FAILED) {
             peg$savedPos = s0;
-            s1 = peg$c84(s2);
+            s1 = peg$c90(s2);
             s0 = s1;
           } else {
             peg$currPos = s0;
@@ -2257,12 +2542,12 @@ var parser=(function() {
     function peg$parsebarewordMeta() {
       var s0;
 
-      if (peg$c86.test(input.charAt(peg$currPos))) {
+      if (peg$c92.test(input.charAt(peg$currPos))) {
         s0 = input.charAt(peg$currPos);
         peg$currPos++;
       } else {
         s0 = peg$FAILED;
-        if (peg$silentFails === 0) { peg$fail(peg$c87); }
+        if (peg$silentFails === 0) { peg$fail(peg$c93); }
       }
 
       return s0;
@@ -2281,19 +2566,19 @@ var parser=(function() {
       if (s1 !== peg$FAILED) {
         s2 = [];
         if (input.charCodeAt(peg$currPos) === 42) {
-          s3 = peg$c88;
+          s3 = peg$c94;
           peg$currPos++;
         } else {
           s3 = peg$FAILED;
-          if (peg$silentFails === 0) { peg$fail(peg$c89); }
+          if (peg$silentFails === 0) { peg$fail(peg$c95); }
         }
         if (s3 === peg$FAILED) {
           if (input.charCodeAt(peg$currPos) === 63) {
-            s3 = peg$c90;
+            s3 = peg$c96;
             peg$currPos++;
           } else {
             s3 = peg$FAILED;
-            if (peg$silentFails === 0) { peg$fail(peg$c91); }
+            if (peg$silentFails === 0) { peg$fail(peg$c97); }
           }
           if (s3 === peg$FAILED) {
             s3 = peg$parsecharacterRange();
@@ -2306,19 +2591,19 @@ var parser=(function() {
           while (s3 !== peg$FAILED) {
             s2.push(s3);
             if (input.charCodeAt(peg$currPos) === 42) {
-              s3 = peg$c88;
+              s3 = peg$c94;
               peg$currPos++;
             } else {
               s3 = peg$FAILED;
-              if (peg$silentFails === 0) { peg$fail(peg$c89); }
+              if (peg$silentFails === 0) { peg$fail(peg$c95); }
             }
             if (s3 === peg$FAILED) {
               if (input.charCodeAt(peg$currPos) === 63) {
-                s3 = peg$c90;
+                s3 = peg$c96;
                 peg$currPos++;
               } else {
                 s3 = peg$FAILED;
-                if (peg$silentFails === 0) { peg$fail(peg$c91); }
+                if (peg$silentFails === 0) { peg$fail(peg$c97); }
               }
               if (s3 === peg$FAILED) {
                 s3 = peg$parsecharacterRange();
@@ -2340,7 +2625,7 @@ var parser=(function() {
           }
           if (s3 !== peg$FAILED) {
             peg$savedPos = s0;
-            s1 = peg$c92();
+            s1 = peg$c98();
             s0 = s1;
           } else {
             peg$currPos = s0;
@@ -2364,21 +2649,21 @@ var parser=(function() {
       s0 = peg$currPos;
       s1 = peg$currPos;
       if (input.charCodeAt(peg$currPos) === 91) {
-        s2 = peg$c73;
+        s2 = peg$c79;
         peg$currPos++;
       } else {
         s2 = peg$FAILED;
-        if (peg$silentFails === 0) { peg$fail(peg$c74); }
+        if (peg$silentFails === 0) { peg$fail(peg$c80); }
       }
       if (s2 !== peg$FAILED) {
         s3 = peg$currPos;
         peg$silentFails++;
         if (input.charCodeAt(peg$currPos) === 45) {
-          s4 = peg$c53;
+          s4 = peg$c59;
           peg$currPos++;
         } else {
           s4 = peg$FAILED;
-          if (peg$silentFails === 0) { peg$fail(peg$c54); }
+          if (peg$silentFails === 0) { peg$fail(peg$c60); }
         }
         peg$silentFails--;
         if (s4 === peg$FAILED) {
@@ -2393,25 +2678,25 @@ var parser=(function() {
             peg$currPos++;
           } else {
             s4 = peg$FAILED;
-            if (peg$silentFails === 0) { peg$fail(peg$c85); }
+            if (peg$silentFails === 0) { peg$fail(peg$c91); }
           }
           if (s4 !== peg$FAILED) {
             if (input.charCodeAt(peg$currPos) === 45) {
-              s5 = peg$c53;
+              s5 = peg$c59;
               peg$currPos++;
             } else {
               s5 = peg$FAILED;
-              if (peg$silentFails === 0) { peg$fail(peg$c54); }
+              if (peg$silentFails === 0) { peg$fail(peg$c60); }
             }
             if (s5 !== peg$FAILED) {
               s6 = peg$currPos;
               peg$silentFails++;
               if (input.charCodeAt(peg$currPos) === 45) {
-                s7 = peg$c53;
+                s7 = peg$c59;
                 peg$currPos++;
               } else {
                 s7 = peg$FAILED;
-                if (peg$silentFails === 0) { peg$fail(peg$c54); }
+                if (peg$silentFails === 0) { peg$fail(peg$c60); }
               }
               peg$silentFails--;
               if (s7 === peg$FAILED) {
@@ -2426,15 +2711,15 @@ var parser=(function() {
                   peg$currPos++;
                 } else {
                   s7 = peg$FAILED;
-                  if (peg$silentFails === 0) { peg$fail(peg$c85); }
+                  if (peg$silentFails === 0) { peg$fail(peg$c91); }
                 }
                 if (s7 !== peg$FAILED) {
                   if (input.charCodeAt(peg$currPos) === 93) {
-                    s8 = peg$c93;
+                    s8 = peg$c99;
                     peg$currPos++;
                   } else {
                     s8 = peg$FAILED;
-                    if (peg$silentFails === 0) { peg$fail(peg$c94); }
+                    if (peg$silentFails === 0) { peg$fail(peg$c100); }
                   }
                   if (s8 !== peg$FAILED) {
                     s2 = [s2, s3, s4, s5, s6, s7, s8];
@@ -2486,7 +2771,7 @@ var parser=(function() {
         peg$currPos++;
       } else {
         s2 = peg$FAILED;
-        if (peg$silentFails === 0) { peg$fail(peg$c85); }
+        if (peg$silentFails === 0) { peg$fail(peg$c91); }
       }
       if (s2 === peg$FAILED) {
         s2 = null;
@@ -2495,11 +2780,11 @@ var parser=(function() {
         s3 = peg$currPos;
         peg$silentFails++;
         if (input.charCodeAt(peg$currPos) === 36) {
-          s4 = peg$c95;
+          s4 = peg$c101;
           peg$currPos++;
         } else {
           s4 = peg$FAILED;
-          if (peg$silentFails === 0) { peg$fail(peg$c96); }
+          if (peg$silentFails === 0) { peg$fail(peg$c102); }
         }
         peg$silentFails--;
         if (s4 === peg$FAILED) {
@@ -2521,11 +2806,11 @@ var parser=(function() {
       }
       if (s1 !== peg$FAILED) {
         if (input.charCodeAt(peg$currPos) === 123) {
-          s2 = peg$c97;
+          s2 = peg$c103;
           peg$currPos++;
         } else {
           s2 = peg$FAILED;
-          if (peg$silentFails === 0) { peg$fail(peg$c98); }
+          if (peg$silentFails === 0) { peg$fail(peg$c104); }
         }
         if (s2 !== peg$FAILED) {
           s3 = [];
@@ -2540,11 +2825,11 @@ var parser=(function() {
           }
           if (s3 !== peg$FAILED) {
             if (input.charCodeAt(peg$currPos) === 125) {
-              s4 = peg$c99;
+              s4 = peg$c105;
               peg$currPos++;
             } else {
               s4 = peg$FAILED;
-              if (peg$silentFails === 0) { peg$fail(peg$c100); }
+              if (peg$silentFails === 0) { peg$fail(peg$c106); }
             }
             if (s4 !== peg$FAILED) {
               s1 = [s1, s2, s3, s4];
@@ -2574,30 +2859,30 @@ var parser=(function() {
 
       s0 = peg$currPos;
       if (input.charCodeAt(peg$currPos) === 39) {
-        s1 = peg$c101;
+        s1 = peg$c107;
         peg$currPos++;
       } else {
         s1 = peg$FAILED;
-        if (peg$silentFails === 0) { peg$fail(peg$c102); }
+        if (peg$silentFails === 0) { peg$fail(peg$c108); }
       }
       if (s1 !== peg$FAILED) {
         s2 = peg$currPos;
         s3 = [];
-        if (peg$c103.test(input.charAt(peg$currPos))) {
+        if (peg$c109.test(input.charAt(peg$currPos))) {
           s4 = input.charAt(peg$currPos);
           peg$currPos++;
         } else {
           s4 = peg$FAILED;
-          if (peg$silentFails === 0) { peg$fail(peg$c104); }
+          if (peg$silentFails === 0) { peg$fail(peg$c110); }
         }
         while (s4 !== peg$FAILED) {
           s3.push(s4);
-          if (peg$c103.test(input.charAt(peg$currPos))) {
+          if (peg$c109.test(input.charAt(peg$currPos))) {
             s4 = input.charAt(peg$currPos);
             peg$currPos++;
           } else {
             s4 = peg$FAILED;
-            if (peg$silentFails === 0) { peg$fail(peg$c104); }
+            if (peg$silentFails === 0) { peg$fail(peg$c110); }
           }
         }
         if (s3 !== peg$FAILED) {
@@ -2607,15 +2892,15 @@ var parser=(function() {
         }
         if (s2 !== peg$FAILED) {
           if (input.charCodeAt(peg$currPos) === 39) {
-            s3 = peg$c101;
+            s3 = peg$c107;
             peg$currPos++;
           } else {
             s3 = peg$FAILED;
-            if (peg$silentFails === 0) { peg$fail(peg$c102); }
+            if (peg$silentFails === 0) { peg$fail(peg$c108); }
           }
           if (s3 !== peg$FAILED) {
             peg$savedPos = s0;
-            s1 = peg$c105(s2);
+            s1 = peg$c111(s2);
             s0 = s1;
           } else {
             peg$currPos = s0;
@@ -2638,11 +2923,11 @@ var parser=(function() {
 
       s0 = peg$currPos;
       if (input.charCodeAt(peg$currPos) === 34) {
-        s1 = peg$c106;
+        s1 = peg$c112;
         peg$currPos++;
       } else {
         s1 = peg$FAILED;
-        if (peg$silentFails === 0) { peg$fail(peg$c107); }
+        if (peg$silentFails === 0) { peg$fail(peg$c113); }
       }
       if (s1 !== peg$FAILED) {
         s2 = [];
@@ -2677,15 +2962,15 @@ var parser=(function() {
         }
         if (s2 !== peg$FAILED) {
           if (input.charCodeAt(peg$currPos) === 34) {
-            s3 = peg$c106;
+            s3 = peg$c112;
             peg$currPos++;
           } else {
             s3 = peg$FAILED;
-            if (peg$silentFails === 0) { peg$fail(peg$c107); }
+            if (peg$silentFails === 0) { peg$fail(peg$c113); }
           }
           if (s3 !== peg$FAILED) {
             peg$savedPos = s0;
-            s1 = peg$c108(s2);
+            s1 = peg$c114(s2);
             s0 = s1;
           } else {
             peg$currPos = s0;
@@ -2708,17 +2993,17 @@ var parser=(function() {
 
       s0 = peg$currPos;
       if (input.charCodeAt(peg$currPos) === 92) {
-        s1 = peg$c82;
+        s1 = peg$c88;
         peg$currPos++;
       } else {
         s1 = peg$FAILED;
-        if (peg$silentFails === 0) { peg$fail(peg$c83); }
+        if (peg$silentFails === 0) { peg$fail(peg$c89); }
       }
       if (s1 !== peg$FAILED) {
         s2 = peg$parsedoubleQuoteMeta();
         if (s2 !== peg$FAILED) {
           peg$savedPos = s0;
-          s1 = peg$c84(s2);
+          s1 = peg$c90(s2);
           s0 = s1;
         } else {
           peg$currPos = s0;
@@ -2730,16 +3015,16 @@ var parser=(function() {
       }
       if (s0 === peg$FAILED) {
         s0 = peg$currPos;
-        if (input.substr(peg$currPos, 2) === peg$c109) {
-          s1 = peg$c109;
+        if (input.substr(peg$currPos, 2) === peg$c115) {
+          s1 = peg$c115;
           peg$currPos += 2;
         } else {
           s1 = peg$FAILED;
-          if (peg$silentFails === 0) { peg$fail(peg$c110); }
+          if (peg$silentFails === 0) { peg$fail(peg$c116); }
         }
         if (s1 !== peg$FAILED) {
           peg$savedPos = s0;
-          s1 = peg$c111();
+          s1 = peg$c117();
         }
         s0 = s1;
         if (s0 === peg$FAILED) {
@@ -2760,11 +3045,11 @@ var parser=(function() {
               peg$currPos++;
             } else {
               s2 = peg$FAILED;
-              if (peg$silentFails === 0) { peg$fail(peg$c85); }
+              if (peg$silentFails === 0) { peg$fail(peg$c91); }
             }
             if (s2 !== peg$FAILED) {
               peg$savedPos = s0;
-              s1 = peg$c84(s2);
+              s1 = peg$c90(s2);
               s0 = s1;
             } else {
               peg$currPos = s0;
@@ -2784,27 +3069,27 @@ var parser=(function() {
       var s0;
 
       if (input.charCodeAt(peg$currPos) === 34) {
-        s0 = peg$c106;
+        s0 = peg$c112;
         peg$currPos++;
       } else {
         s0 = peg$FAILED;
-        if (peg$silentFails === 0) { peg$fail(peg$c107); }
+        if (peg$silentFails === 0) { peg$fail(peg$c113); }
       }
       if (s0 === peg$FAILED) {
         if (input.charCodeAt(peg$currPos) === 36) {
-          s0 = peg$c95;
+          s0 = peg$c101;
           peg$currPos++;
         } else {
           s0 = peg$FAILED;
-          if (peg$silentFails === 0) { peg$fail(peg$c96); }
+          if (peg$silentFails === 0) { peg$fail(peg$c102); }
         }
         if (s0 === peg$FAILED) {
           if (input.charCodeAt(peg$currPos) === 96) {
-            s0 = peg$c112;
+            s0 = peg$c118;
             peg$currPos++;
           } else {
             s0 = peg$FAILED;
-            if (peg$silentFails === 0) { peg$fail(peg$c113); }
+            if (peg$silentFails === 0) { peg$fail(peg$c119); }
           }
         }
       }
@@ -2815,11 +3100,14 @@ var parser=(function() {
     function peg$parseexpandsInQuotes() {
       var s0;
 
-      s0 = peg$parsecommandSubstitution();
+      s0 = peg$parsearithmeticSubstitution();
       if (s0 === peg$FAILED) {
-        s0 = peg$parseenvironmentVariable();
+        s0 = peg$parsecommandSubstitution();
         if (s0 === peg$FAILED) {
-          s0 = peg$parsevariableSubstitution();
+          s0 = peg$parseenvironmentVariable();
+          if (s0 === peg$FAILED) {
+            s0 = peg$parsevariableSubstitution();
+          }
         }
       }
 
@@ -2831,17 +3119,17 @@ var parser=(function() {
 
       s0 = peg$currPos;
       if (input.charCodeAt(peg$currPos) === 36) {
-        s1 = peg$c95;
+        s1 = peg$c101;
         peg$currPos++;
       } else {
         s1 = peg$FAILED;
-        if (peg$silentFails === 0) { peg$fail(peg$c96); }
+        if (peg$silentFails === 0) { peg$fail(peg$c102); }
       }
       if (s1 !== peg$FAILED) {
         s2 = peg$parsereadableVariableName();
         if (s2 !== peg$FAILED) {
           peg$savedPos = s0;
-          s1 = peg$c114(s2);
+          s1 = peg$c120(s2);
           s0 = s1;
         } else {
           peg$currPos = s0;
@@ -2860,22 +3148,22 @@ var parser=(function() {
 
       s0 = peg$currPos;
       s1 = [];
-      if (peg$c115.test(input.charAt(peg$currPos))) {
+      if (peg$c121.test(input.charAt(peg$currPos))) {
         s2 = input.charAt(peg$currPos);
         peg$currPos++;
       } else {
         s2 = peg$FAILED;
-        if (peg$silentFails === 0) { peg$fail(peg$c116); }
+        if (peg$silentFails === 0) { peg$fail(peg$c122); }
       }
       if (s2 !== peg$FAILED) {
         while (s2 !== peg$FAILED) {
           s1.push(s2);
-          if (peg$c115.test(input.charAt(peg$currPos))) {
+          if (peg$c121.test(input.charAt(peg$currPos))) {
             s2 = input.charAt(peg$currPos);
             peg$currPos++;
           } else {
             s2 = peg$FAILED;
-            if (peg$silentFails === 0) { peg$fail(peg$c116); }
+            if (peg$silentFails === 0) { peg$fail(peg$c122); }
           }
         }
       } else {
@@ -2883,7 +3171,7 @@ var parser=(function() {
       }
       if (s1 !== peg$FAILED) {
         peg$savedPos = s0;
-        s1 = peg$c117();
+        s1 = peg$c123();
       }
       s0 = s1;
 
@@ -2896,11 +3184,11 @@ var parser=(function() {
       s0 = peg$parsewritableVariableName();
       if (s0 === peg$FAILED) {
         if (input.charCodeAt(peg$currPos) === 63) {
-          s0 = peg$c90;
+          s0 = peg$c96;
           peg$currPos++;
         } else {
           s0 = peg$FAILED;
-          if (peg$silentFails === 0) { peg$fail(peg$c91); }
+          if (peg$silentFails === 0) { peg$fail(peg$c97); }
         }
       }
 
@@ -2911,43 +3199,43 @@ var parser=(function() {
       var s0, s1, s2, s3;
 
       s0 = peg$currPos;
-      if (input.substr(peg$currPos, 2) === peg$c118) {
-        s1 = peg$c118;
+      if (input.substr(peg$currPos, 2) === peg$c124) {
+        s1 = peg$c124;
         peg$currPos += 2;
       } else {
         s1 = peg$FAILED;
-        if (peg$silentFails === 0) { peg$fail(peg$c119); }
+        if (peg$silentFails === 0) { peg$fail(peg$c125); }
       }
       if (s1 !== peg$FAILED) {
         s2 = [];
-        if (peg$c120.test(input.charAt(peg$currPos))) {
+        if (peg$c126.test(input.charAt(peg$currPos))) {
           s3 = input.charAt(peg$currPos);
           peg$currPos++;
         } else {
           s3 = peg$FAILED;
-          if (peg$silentFails === 0) { peg$fail(peg$c121); }
+          if (peg$silentFails === 0) { peg$fail(peg$c127); }
         }
         while (s3 !== peg$FAILED) {
           s2.push(s3);
-          if (peg$c120.test(input.charAt(peg$currPos))) {
+          if (peg$c126.test(input.charAt(peg$currPos))) {
             s3 = input.charAt(peg$currPos);
             peg$currPos++;
           } else {
             s3 = peg$FAILED;
-            if (peg$silentFails === 0) { peg$fail(peg$c121); }
+            if (peg$silentFails === 0) { peg$fail(peg$c127); }
           }
         }
         if (s2 !== peg$FAILED) {
           if (input.charCodeAt(peg$currPos) === 125) {
-            s3 = peg$c99;
+            s3 = peg$c105;
             peg$currPos++;
           } else {
             s3 = peg$FAILED;
-            if (peg$silentFails === 0) { peg$fail(peg$c100); }
+            if (peg$silentFails === 0) { peg$fail(peg$c106); }
           }
           if (s3 !== peg$FAILED) {
             peg$savedPos = s0;
-            s1 = peg$c122(s2);
+            s1 = peg$c128(s2);
             s0 = s1;
           } else {
             peg$currPos = s0;
@@ -2980,26 +3268,67 @@ var parser=(function() {
       var s0, s1, s2, s3;
 
       s0 = peg$currPos;
-      if (input.substr(peg$currPos, 2) === peg$c123) {
-        s1 = peg$c123;
+      if (input.substr(peg$currPos, 2) === peg$c129) {
+        s1 = peg$c129;
         peg$currPos += 2;
       } else {
         s1 = peg$FAILED;
-        if (peg$silentFails === 0) { peg$fail(peg$c124); }
+        if (peg$silentFails === 0) { peg$fail(peg$c130); }
       }
       if (s1 !== peg$FAILED) {
         s2 = peg$parsestatementList();
         if (s2 !== peg$FAILED) {
           if (input.charCodeAt(peg$currPos) === 41) {
-            s3 = peg$c11;
+            s3 = peg$c17;
             peg$currPos++;
+          } else {
+            s3 = peg$FAILED;
+            if (peg$silentFails === 0) { peg$fail(peg$c18); }
+          }
+          if (s3 !== peg$FAILED) {
+            peg$savedPos = s0;
+            s1 = peg$c131(s2);
+            s0 = s1;
+          } else {
+            peg$currPos = s0;
+            s0 = peg$FAILED;
+          }
+        } else {
+          peg$currPos = s0;
+          s0 = peg$FAILED;
+        }
+      } else {
+        peg$currPos = s0;
+        s0 = peg$FAILED;
+      }
+
+      return s0;
+    }
+
+    function peg$parsearithmeticSubstitution() {
+      var s0, s1, s2, s3;
+
+      s0 = peg$currPos;
+      if (input.substr(peg$currPos, 3) === peg$c132) {
+        s1 = peg$c132;
+        peg$currPos += 3;
+      } else {
+        s1 = peg$FAILED;
+        if (peg$silentFails === 0) { peg$fail(peg$c133); }
+      }
+      if (s1 !== peg$FAILED) {
+        s2 = peg$parsearithmetic();
+        if (s2 !== peg$FAILED) {
+          if (input.substr(peg$currPos, 2) === peg$c11) {
+            s3 = peg$c11;
+            peg$currPos += 2;
           } else {
             s3 = peg$FAILED;
             if (peg$silentFails === 0) { peg$fail(peg$c12); }
           }
           if (s3 !== peg$FAILED) {
             peg$savedPos = s0;
-            s1 = peg$c125(s2);
+            s1 = peg$c134(s2);
             s0 = s1;
           } else {
             peg$currPos = s0;
@@ -3022,11 +3351,11 @@ var parser=(function() {
 
       s0 = peg$currPos;
       if (input.charCodeAt(peg$currPos) === 96) {
-        s1 = peg$c112;
+        s1 = peg$c118;
         peg$currPos++;
       } else {
         s1 = peg$FAILED;
-        if (peg$silentFails === 0) { peg$fail(peg$c113); }
+        if (peg$silentFails === 0) { peg$fail(peg$c119); }
       }
       if (s1 !== peg$FAILED) {
         s2 = [];
@@ -3041,15 +3370,15 @@ var parser=(function() {
         }
         if (s2 !== peg$FAILED) {
           if (input.charCodeAt(peg$currPos) === 96) {
-            s3 = peg$c112;
+            s3 = peg$c118;
             peg$currPos++;
           } else {
             s3 = peg$FAILED;
-            if (peg$silentFails === 0) { peg$fail(peg$c113); }
+            if (peg$silentFails === 0) { peg$fail(peg$c119); }
           }
           if (s3 !== peg$FAILED) {
             peg$savedPos = s0;
-            s1 = peg$c126(s2);
+            s1 = peg$c135(s2);
             s0 = s1;
           } else {
             peg$currPos = s0;
@@ -3071,30 +3400,30 @@ var parser=(function() {
       var s0, s1, s2;
 
       s0 = peg$currPos;
-      if (input.substr(peg$currPos, 2) === peg$c127) {
-        s1 = peg$c127;
+      if (input.substr(peg$currPos, 2) === peg$c136) {
+        s1 = peg$c136;
         peg$currPos += 2;
       } else {
         s1 = peg$FAILED;
-        if (peg$silentFails === 0) { peg$fail(peg$c128); }
+        if (peg$silentFails === 0) { peg$fail(peg$c137); }
       }
       if (s1 !== peg$FAILED) {
         peg$savedPos = s0;
-        s1 = peg$c129();
+        s1 = peg$c138();
       }
       s0 = s1;
       if (s0 === peg$FAILED) {
         s0 = peg$currPos;
-        if (input.substr(peg$currPos, 2) === peg$c109) {
-          s1 = peg$c109;
+        if (input.substr(peg$currPos, 2) === peg$c115) {
+          s1 = peg$c115;
           peg$currPos += 2;
         } else {
           s1 = peg$FAILED;
-          if (peg$silentFails === 0) { peg$fail(peg$c110); }
+          if (peg$silentFails === 0) { peg$fail(peg$c116); }
         }
         if (s1 !== peg$FAILED) {
           peg$savedPos = s0;
-          s1 = peg$c111();
+          s1 = peg$c117();
         }
         s0 = s1;
         if (s0 === peg$FAILED) {
@@ -3102,11 +3431,11 @@ var parser=(function() {
           s1 = peg$currPos;
           peg$silentFails++;
           if (input.charCodeAt(peg$currPos) === 96) {
-            s2 = peg$c112;
+            s2 = peg$c118;
             peg$currPos++;
           } else {
             s2 = peg$FAILED;
-            if (peg$silentFails === 0) { peg$fail(peg$c113); }
+            if (peg$silentFails === 0) { peg$fail(peg$c119); }
           }
           peg$silentFails--;
           if (s2 === peg$FAILED) {
@@ -3121,11 +3450,11 @@ var parser=(function() {
               peg$currPos++;
             } else {
               s2 = peg$FAILED;
-              if (peg$silentFails === 0) { peg$fail(peg$c85); }
+              if (peg$silentFails === 0) { peg$fail(peg$c91); }
             }
             if (s2 !== peg$FAILED) {
               peg$savedPos = s0;
-              s1 = peg$c84(s2);
+              s1 = peg$c90(s2);
               s0 = s1;
             } else {
               peg$currPos = s0;
@@ -3145,34 +3474,34 @@ var parser=(function() {
       var s0, s1, s2, s3, s4;
 
       s0 = peg$currPos;
-      if (peg$c130.test(input.charAt(peg$currPos))) {
+      if (peg$c139.test(input.charAt(peg$currPos))) {
         s1 = input.charAt(peg$currPos);
         peg$currPos++;
       } else {
         s1 = peg$FAILED;
-        if (peg$silentFails === 0) { peg$fail(peg$c131); }
+        if (peg$silentFails === 0) { peg$fail(peg$c140); }
       }
       if (s1 !== peg$FAILED) {
         if (input.charCodeAt(peg$currPos) === 40) {
-          s2 = peg$c9;
+          s2 = peg$c15;
           peg$currPos++;
         } else {
           s2 = peg$FAILED;
-          if (peg$silentFails === 0) { peg$fail(peg$c10); }
+          if (peg$silentFails === 0) { peg$fail(peg$c16); }
         }
         if (s2 !== peg$FAILED) {
           s3 = peg$parsestatementList();
           if (s3 !== peg$FAILED) {
             if (input.charCodeAt(peg$currPos) === 41) {
-              s4 = peg$c11;
+              s4 = peg$c17;
               peg$currPos++;
             } else {
               s4 = peg$FAILED;
-              if (peg$silentFails === 0) { peg$fail(peg$c12); }
+              if (peg$silentFails === 0) { peg$fail(peg$c18); }
             }
             if (s4 !== peg$FAILED) {
               peg$savedPos = s0;
-              s1 = peg$c132(s1, s3);
+              s1 = peg$c141(s1, s3);
               s0 = s1;
             } else {
               peg$currPos = s0;
@@ -3217,35 +3546,35 @@ var parser=(function() {
         s1 = null;
       }
       if (s1 !== peg$FAILED) {
-        if (input.substr(peg$currPos, 2) === peg$c133) {
-          s2 = peg$c133;
+        if (input.substr(peg$currPos, 2) === peg$c142) {
+          s2 = peg$c142;
           peg$currPos += 2;
         } else {
           s2 = peg$FAILED;
-          if (peg$silentFails === 0) { peg$fail(peg$c134); }
+          if (peg$silentFails === 0) { peg$fail(peg$c143); }
         }
         if (s2 === peg$FAILED) {
-          if (input.substr(peg$currPos, 2) === peg$c135) {
-            s2 = peg$c135;
+          if (input.substr(peg$currPos, 2) === peg$c144) {
+            s2 = peg$c144;
             peg$currPos += 2;
           } else {
             s2 = peg$FAILED;
-            if (peg$silentFails === 0) { peg$fail(peg$c136); }
+            if (peg$silentFails === 0) { peg$fail(peg$c145); }
           }
         }
         if (s2 !== peg$FAILED) {
           s3 = peg$parsefd();
           if (s3 !== peg$FAILED) {
             if (input.charCodeAt(peg$currPos) === 45) {
-              s4 = peg$c53;
+              s4 = peg$c59;
               peg$currPos++;
             } else {
               s4 = peg$FAILED;
-              if (peg$silentFails === 0) { peg$fail(peg$c54); }
+              if (peg$silentFails === 0) { peg$fail(peg$c60); }
             }
             if (s4 !== peg$FAILED) {
               peg$savedPos = s0;
-              s1 = peg$c137(s1, s2, s3);
+              s1 = peg$c146(s1, s2, s3);
               s0 = s1;
             } else {
               peg$currPos = s0;
@@ -3276,20 +3605,20 @@ var parser=(function() {
         s1 = null;
       }
       if (s1 !== peg$FAILED) {
-        if (input.substr(peg$currPos, 2) === peg$c133) {
-          s2 = peg$c133;
+        if (input.substr(peg$currPos, 2) === peg$c142) {
+          s2 = peg$c142;
           peg$currPos += 2;
         } else {
           s2 = peg$FAILED;
-          if (peg$silentFails === 0) { peg$fail(peg$c134); }
+          if (peg$silentFails === 0) { peg$fail(peg$c143); }
         }
         if (s2 === peg$FAILED) {
-          if (input.substr(peg$currPos, 2) === peg$c135) {
-            s2 = peg$c135;
+          if (input.substr(peg$currPos, 2) === peg$c144) {
+            s2 = peg$c144;
             peg$currPos += 2;
           } else {
             s2 = peg$FAILED;
-            if (peg$silentFails === 0) { peg$fail(peg$c136); }
+            if (peg$silentFails === 0) { peg$fail(peg$c145); }
           }
         }
         if (s2 !== peg$FAILED) {
@@ -3303,7 +3632,7 @@ var parser=(function() {
             s4 = peg$parsefd();
             if (s4 !== peg$FAILED) {
               peg$savedPos = s0;
-              s1 = peg$c138(s1, s2, s4);
+              s1 = peg$c147(s1, s2, s4);
               s0 = s1;
             } else {
               peg$currPos = s0;
@@ -3346,7 +3675,7 @@ var parser=(function() {
             s4 = peg$parseargument();
             if (s4 !== peg$FAILED) {
               peg$savedPos = s0;
-              s1 = peg$c139(s1, s2, s4);
+              s1 = peg$c148(s1, s2, s4);
               s0 = s1;
             } else {
               peg$currPos = s0;
@@ -3371,52 +3700,52 @@ var parser=(function() {
     function peg$parseredirectionOperator() {
       var s0;
 
-      if (input.substr(peg$currPos, 2) === peg$c140) {
-        s0 = peg$c140;
+      if (input.substr(peg$currPos, 2) === peg$c149) {
+        s0 = peg$c149;
         peg$currPos += 2;
       } else {
         s0 = peg$FAILED;
-        if (peg$silentFails === 0) { peg$fail(peg$c141); }
+        if (peg$silentFails === 0) { peg$fail(peg$c150); }
       }
       if (s0 === peg$FAILED) {
-        if (input.substr(peg$currPos, 2) === peg$c142) {
-          s0 = peg$c142;
+        if (input.substr(peg$currPos, 2) === peg$c151) {
+          s0 = peg$c151;
           peg$currPos += 2;
         } else {
           s0 = peg$FAILED;
-          if (peg$silentFails === 0) { peg$fail(peg$c143); }
+          if (peg$silentFails === 0) { peg$fail(peg$c152); }
         }
         if (s0 === peg$FAILED) {
-          if (input.substr(peg$currPos, 3) === peg$c144) {
-            s0 = peg$c144;
+          if (input.substr(peg$currPos, 3) === peg$c153) {
+            s0 = peg$c153;
             peg$currPos += 3;
           } else {
             s0 = peg$FAILED;
-            if (peg$silentFails === 0) { peg$fail(peg$c145); }
+            if (peg$silentFails === 0) { peg$fail(peg$c154); }
           }
           if (s0 === peg$FAILED) {
-            if (input.substr(peg$currPos, 2) === peg$c146) {
-              s0 = peg$c146;
+            if (input.substr(peg$currPos, 2) === peg$c155) {
+              s0 = peg$c155;
               peg$currPos += 2;
             } else {
               s0 = peg$FAILED;
-              if (peg$silentFails === 0) { peg$fail(peg$c147); }
+              if (peg$silentFails === 0) { peg$fail(peg$c156); }
             }
             if (s0 === peg$FAILED) {
               if (input.charCodeAt(peg$currPos) === 60) {
-                s0 = peg$c148;
+                s0 = peg$c157;
                 peg$currPos++;
               } else {
                 s0 = peg$FAILED;
-                if (peg$silentFails === 0) { peg$fail(peg$c149); }
+                if (peg$silentFails === 0) { peg$fail(peg$c158); }
               }
               if (s0 === peg$FAILED) {
                 if (input.charCodeAt(peg$currPos) === 62) {
-                  s0 = peg$c150;
+                  s0 = peg$c159;
                   peg$currPos++;
                 } else {
                   s0 = peg$FAILED;
-                  if (peg$silentFails === 0) { peg$fail(peg$c151); }
+                  if (peg$silentFails === 0) { peg$fail(peg$c160); }
                 }
               }
             }
@@ -3432,22 +3761,22 @@ var parser=(function() {
 
       s0 = peg$currPos;
       s1 = [];
-      if (peg$c152.test(input.charAt(peg$currPos))) {
+      if (peg$c161.test(input.charAt(peg$currPos))) {
         s2 = input.charAt(peg$currPos);
         peg$currPos++;
       } else {
         s2 = peg$FAILED;
-        if (peg$silentFails === 0) { peg$fail(peg$c153); }
+        if (peg$silentFails === 0) { peg$fail(peg$c162); }
       }
       if (s2 !== peg$FAILED) {
         while (s2 !== peg$FAILED) {
           s1.push(s2);
-          if (peg$c152.test(input.charAt(peg$currPos))) {
+          if (peg$c161.test(input.charAt(peg$currPos))) {
             s2 = input.charAt(peg$currPos);
             peg$currPos++;
           } else {
             s2 = peg$FAILED;
-            if (peg$silentFails === 0) { peg$fail(peg$c153); }
+            if (peg$silentFails === 0) { peg$fail(peg$c162); }
           }
         }
       } else {
@@ -3455,7 +3784,7 @@ var parser=(function() {
       }
       if (s1 !== peg$FAILED) {
         peg$savedPos = s0;
-        s1 = peg$c154(s1);
+        s1 = peg$c163(s1);
       }
       s0 = s1;
 
@@ -3474,33 +3803,33 @@ var parser=(function() {
       }
       if (s1 !== peg$FAILED) {
         if (input.charCodeAt(peg$currPos) === 38) {
-          s2 = peg$c155;
+          s2 = peg$c164;
           peg$currPos++;
         } else {
           s2 = peg$FAILED;
-          if (peg$silentFails === 0) { peg$fail(peg$c156); }
+          if (peg$silentFails === 0) { peg$fail(peg$c165); }
         }
         if (s2 === peg$FAILED) {
           if (input.charCodeAt(peg$currPos) === 59) {
-            s2 = peg$c45;
+            s2 = peg$c51;
             peg$currPos++;
           } else {
             s2 = peg$FAILED;
-            if (peg$silentFails === 0) { peg$fail(peg$c46); }
+            if (peg$silentFails === 0) { peg$fail(peg$c52); }
           }
           if (s2 === peg$FAILED) {
             if (input.charCodeAt(peg$currPos) === 10) {
-              s2 = peg$c47;
+              s2 = peg$c53;
               peg$currPos++;
             } else {
               s2 = peg$FAILED;
-              if (peg$silentFails === 0) { peg$fail(peg$c48); }
+              if (peg$silentFails === 0) { peg$fail(peg$c54); }
             }
           }
         }
         if (s2 !== peg$FAILED) {
           peg$savedPos = s0;
-          s1 = peg$c157(s2);
+          s1 = peg$c166(s2);
           s0 = s1;
         } else {
           peg$currPos = s0;
@@ -3519,11 +3848,11 @@ var parser=(function() {
 
       s0 = peg$currPos;
       if (input.charCodeAt(peg$currPos) === 124) {
-        s1 = peg$c158;
+        s1 = peg$c167;
         peg$currPos++;
       } else {
         s1 = peg$FAILED;
-        if (peg$silentFails === 0) { peg$fail(peg$c159); }
+        if (peg$silentFails === 0) { peg$fail(peg$c168); }
       }
       if (s1 !== peg$FAILED) {
         s2 = [];
@@ -3536,7 +3865,7 @@ var parser=(function() {
           s3 = peg$parsecommand();
           if (s3 !== peg$FAILED) {
             peg$savedPos = s0;
-            s1 = peg$c160(s3);
+            s1 = peg$c169(s3);
             s0 = s1;
           } else {
             peg$currPos = s0;
@@ -3559,25 +3888,25 @@ var parser=(function() {
 
       peg$silentFails++;
       if (input.charCodeAt(peg$currPos) === 32) {
-        s0 = peg$c162;
+        s0 = peg$c171;
         peg$currPos++;
       } else {
         s0 = peg$FAILED;
-        if (peg$silentFails === 0) { peg$fail(peg$c163); }
+        if (peg$silentFails === 0) { peg$fail(peg$c172); }
       }
       if (s0 === peg$FAILED) {
         if (input.charCodeAt(peg$currPos) === 9) {
-          s0 = peg$c164;
+          s0 = peg$c173;
           peg$currPos++;
         } else {
           s0 = peg$FAILED;
-          if (peg$silentFails === 0) { peg$fail(peg$c165); }
+          if (peg$silentFails === 0) { peg$fail(peg$c174); }
         }
       }
       peg$silentFails--;
       if (s0 === peg$FAILED) {
         s1 = peg$FAILED;
-        if (peg$silentFails === 0) { peg$fail(peg$c161); }
+        if (peg$silentFails === 0) { peg$fail(peg$c170); }
       }
 
       return s0;
@@ -3589,11 +3918,11 @@ var parser=(function() {
       s0 = peg$parsespace();
       if (s0 === peg$FAILED) {
         if (input.charCodeAt(peg$currPos) === 10) {
-          s0 = peg$c47;
+          s0 = peg$c53;
           peg$currPos++;
         } else {
           s0 = peg$FAILED;
-          if (peg$silentFails === 0) { peg$fail(peg$c48); }
+          if (peg$silentFails === 0) { peg$fail(peg$c54); }
         }
         if (s0 === peg$FAILED) {
           s0 = peg$parsecomment();
@@ -3609,38 +3938,38 @@ var parser=(function() {
       peg$silentFails++;
       s0 = peg$currPos;
       if (input.charCodeAt(peg$currPos) === 35) {
-        s1 = peg$c79;
+        s1 = peg$c85;
         peg$currPos++;
       } else {
         s1 = peg$FAILED;
-        if (peg$silentFails === 0) { peg$fail(peg$c80); }
+        if (peg$silentFails === 0) { peg$fail(peg$c86); }
       }
       if (s1 !== peg$FAILED) {
         s2 = [];
-        if (peg$c63.test(input.charAt(peg$currPos))) {
+        if (peg$c69.test(input.charAt(peg$currPos))) {
           s3 = input.charAt(peg$currPos);
           peg$currPos++;
         } else {
           s3 = peg$FAILED;
-          if (peg$silentFails === 0) { peg$fail(peg$c64); }
+          if (peg$silentFails === 0) { peg$fail(peg$c70); }
         }
         while (s3 !== peg$FAILED) {
           s2.push(s3);
-          if (peg$c63.test(input.charAt(peg$currPos))) {
+          if (peg$c69.test(input.charAt(peg$currPos))) {
             s3 = input.charAt(peg$currPos);
             peg$currPos++;
           } else {
             s3 = peg$FAILED;
-            if (peg$silentFails === 0) { peg$fail(peg$c64); }
+            if (peg$silentFails === 0) { peg$fail(peg$c70); }
           }
         }
         if (s2 !== peg$FAILED) {
           if (input.charCodeAt(peg$currPos) === 10) {
-            s3 = peg$c47;
+            s3 = peg$c53;
             peg$currPos++;
           } else {
             s3 = peg$FAILED;
-            if (peg$silentFails === 0) { peg$fail(peg$c48); }
+            if (peg$silentFails === 0) { peg$fail(peg$c54); }
           }
           if (s3 === peg$FAILED) {
             s3 = peg$parseEOF();
@@ -3663,7 +3992,7 @@ var parser=(function() {
       peg$silentFails--;
       if (s0 === peg$FAILED) {
         s1 = peg$FAILED;
-        if (peg$silentFails === 0) { peg$fail(peg$c166); }
+        if (peg$silentFails === 0) { peg$fail(peg$c175); }
       }
 
       return s0;
@@ -3673,108 +4002,108 @@ var parser=(function() {
       var s0, s1, s2, s3;
 
       s0 = peg$currPos;
-      if (input.substr(peg$currPos, 5) === peg$c31) {
-        s1 = peg$c31;
+      if (input.substr(peg$currPos, 5) === peg$c37) {
+        s1 = peg$c37;
         peg$currPos += 5;
       } else {
         s1 = peg$FAILED;
-        if (peg$silentFails === 0) { peg$fail(peg$c32); }
+        if (peg$silentFails === 0) { peg$fail(peg$c38); }
       }
       if (s1 === peg$FAILED) {
-        if (input.substr(peg$currPos, 5) === peg$c33) {
-          s1 = peg$c33;
+        if (input.substr(peg$currPos, 5) === peg$c39) {
+          s1 = peg$c39;
           peg$currPos += 5;
         } else {
           s1 = peg$FAILED;
-          if (peg$silentFails === 0) { peg$fail(peg$c34); }
+          if (peg$silentFails === 0) { peg$fail(peg$c40); }
         }
         if (s1 === peg$FAILED) {
-          if (input.substr(peg$currPos, 3) === peg$c41) {
-            s1 = peg$c41;
+          if (input.substr(peg$currPos, 3) === peg$c47) {
+            s1 = peg$c47;
             peg$currPos += 3;
           } else {
             s1 = peg$FAILED;
-            if (peg$silentFails === 0) { peg$fail(peg$c42); }
+            if (peg$silentFails === 0) { peg$fail(peg$c48); }
           }
           if (s1 === peg$FAILED) {
-            if (input.substr(peg$currPos, 4) === peg$c37) {
-              s1 = peg$c37;
+            if (input.substr(peg$currPos, 4) === peg$c43) {
+              s1 = peg$c43;
               peg$currPos += 4;
             } else {
               s1 = peg$FAILED;
-              if (peg$silentFails === 0) { peg$fail(peg$c38); }
+              if (peg$silentFails === 0) { peg$fail(peg$c44); }
             }
             if (s1 === peg$FAILED) {
-              if (input.substr(peg$currPos, 2) === peg$c35) {
-                s1 = peg$c35;
+              if (input.substr(peg$currPos, 2) === peg$c41) {
+                s1 = peg$c41;
                 peg$currPos += 2;
               } else {
                 s1 = peg$FAILED;
-                if (peg$silentFails === 0) { peg$fail(peg$c36); }
+                if (peg$silentFails === 0) { peg$fail(peg$c42); }
               }
               if (s1 === peg$FAILED) {
-                if (input.substr(peg$currPos, 4) === peg$c167) {
-                  s1 = peg$c167;
+                if (input.substr(peg$currPos, 4) === peg$c176) {
+                  s1 = peg$c176;
                   peg$currPos += 4;
                 } else {
                   s1 = peg$FAILED;
-                  if (peg$silentFails === 0) { peg$fail(peg$c168); }
+                  if (peg$silentFails === 0) { peg$fail(peg$c177); }
                 }
                 if (s1 === peg$FAILED) {
-                  if (input.substr(peg$currPos, 4) === peg$c169) {
-                    s1 = peg$c169;
+                  if (input.substr(peg$currPos, 4) === peg$c178) {
+                    s1 = peg$c178;
                     peg$currPos += 4;
                   } else {
                     s1 = peg$FAILED;
-                    if (peg$silentFails === 0) { peg$fail(peg$c170); }
+                    if (peg$silentFails === 0) { peg$fail(peg$c179); }
                   }
                   if (s1 === peg$FAILED) {
-                    if (input.substr(peg$currPos, 2) === peg$c18) {
-                      s1 = peg$c18;
+                    if (input.substr(peg$currPos, 2) === peg$c24) {
+                      s1 = peg$c24;
                       peg$currPos += 2;
                     } else {
                       s1 = peg$FAILED;
-                      if (peg$silentFails === 0) { peg$fail(peg$c19); }
+                      if (peg$silentFails === 0) { peg$fail(peg$c25); }
                     }
                     if (s1 === peg$FAILED) {
-                      if (input.substr(peg$currPos, 4) === peg$c20) {
-                        s1 = peg$c20;
+                      if (input.substr(peg$currPos, 4) === peg$c26) {
+                        s1 = peg$c26;
                         peg$currPos += 4;
                       } else {
                         s1 = peg$FAILED;
-                        if (peg$silentFails === 0) { peg$fail(peg$c21); }
+                        if (peg$silentFails === 0) { peg$fail(peg$c27); }
                       }
                       if (s1 === peg$FAILED) {
-                        if (input.substr(peg$currPos, 4) === peg$c22) {
-                          s1 = peg$c22;
+                        if (input.substr(peg$currPos, 4) === peg$c28) {
+                          s1 = peg$c28;
                           peg$currPos += 4;
                         } else {
                           s1 = peg$FAILED;
-                          if (peg$silentFails === 0) { peg$fail(peg$c23); }
+                          if (peg$silentFails === 0) { peg$fail(peg$c29); }
                         }
                         if (s1 === peg$FAILED) {
-                          if (input.substr(peg$currPos, 4) === peg$c27) {
-                            s1 = peg$c27;
+                          if (input.substr(peg$currPos, 4) === peg$c33) {
+                            s1 = peg$c33;
                             peg$currPos += 4;
                           } else {
                             s1 = peg$FAILED;
-                            if (peg$silentFails === 0) { peg$fail(peg$c28); }
+                            if (peg$silentFails === 0) { peg$fail(peg$c34); }
                           }
                           if (s1 === peg$FAILED) {
-                            if (input.substr(peg$currPos, 2) === peg$c24) {
-                              s1 = peg$c24;
+                            if (input.substr(peg$currPos, 2) === peg$c30) {
+                              s1 = peg$c30;
                               peg$currPos += 2;
                             } else {
                               s1 = peg$FAILED;
-                              if (peg$silentFails === 0) { peg$fail(peg$c25); }
+                              if (peg$silentFails === 0) { peg$fail(peg$c31); }
                             }
                             if (s1 === peg$FAILED) {
-                              if (input.substr(peg$currPos, 2) === peg$c71) {
-                                s1 = peg$c71;
+                              if (input.substr(peg$currPos, 2) === peg$c77) {
+                                s1 = peg$c77;
                                 peg$currPos += 2;
                               } else {
                                 s1 = peg$FAILED;
-                                if (peg$silentFails === 0) { peg$fail(peg$c72); }
+                                if (peg$silentFails === 0) { peg$fail(peg$c78); }
                               }
                             }
                           }
@@ -3817,52 +4146,3305 @@ var parser=(function() {
       return s0;
     }
 
-    function peg$parsecontinuationStart() {
-      var s0, s1, s2, s3;
+    function peg$parsearithmetic() {
+      var s0, s1;
 
+      peg$silentFails++;
       s0 = peg$currPos;
-      s1 = peg$currPos;
+      s1 = peg$parseaComma();
+      if (s1 !== peg$FAILED) {
+        peg$savedPos = s0;
+        s1 = peg$c181(s1);
+      }
+      s0 = s1;
+      peg$silentFails--;
+      if (s0 === peg$FAILED) {
+        s1 = peg$FAILED;
+        if (peg$silentFails === 0) { peg$fail(peg$c180); }
+      }
+
+      return s0;
+    }
+
+    function peg$parseaComma() {
+      var s0, s1, s2, s3, s4, s5, s6, s7;
+
       peg$silentFails++;
-      s2 = peg$parsekeyword();
-      if (s2 === peg$FAILED) {
-        if (input.charCodeAt(peg$currPos) === 34) {
-          s2 = peg$c106;
-          peg$currPos++;
-        } else {
-          s2 = peg$FAILED;
-          if (peg$silentFails === 0) { peg$fail(peg$c107); }
+      s0 = peg$currPos;
+      s1 = peg$parseaAssign();
+      if (s1 !== peg$FAILED) {
+        s2 = [];
+        s3 = peg$currPos;
+        s4 = [];
+        s5 = peg$parsespaceNL();
+        while (s5 !== peg$FAILED) {
+          s4.push(s5);
+          s5 = peg$parsespaceNL();
         }
-        if (s2 === peg$FAILED) {
-          if (input.charCodeAt(peg$currPos) === 39) {
-            s2 = peg$c101;
+        if (s4 !== peg$FAILED) {
+          if (input.charCodeAt(peg$currPos) === 44) {
+            s5 = peg$c183;
             peg$currPos++;
           } else {
-            s2 = peg$FAILED;
-            if (peg$silentFails === 0) { peg$fail(peg$c102); }
+            s5 = peg$FAILED;
+            if (peg$silentFails === 0) { peg$fail(peg$c184); }
           }
-          if (s2 === peg$FAILED) {
-            if (input.charCodeAt(peg$currPos) === 96) {
-              s2 = peg$c112;
-              peg$currPos++;
-            } else {
-              s2 = peg$FAILED;
-              if (peg$silentFails === 0) { peg$fail(peg$c113); }
+          if (s5 !== peg$FAILED) {
+            s6 = [];
+            s7 = peg$parsespaceNL();
+            while (s7 !== peg$FAILED) {
+              s6.push(s7);
+              s7 = peg$parsespaceNL();
             }
-            if (s2 === peg$FAILED) {
-              if (input.substr(peg$currPos, 2) === peg$c123) {
-                s2 = peg$c123;
-                peg$currPos += 2;
+            if (s6 !== peg$FAILED) {
+              s7 = peg$parseaAssign();
+              if (s7 !== peg$FAILED) {
+                peg$savedPos = s3;
+                s4 = peg$c185(s1, s7);
+                s3 = s4;
               } else {
-                s2 = peg$FAILED;
-                if (peg$silentFails === 0) { peg$fail(peg$c124); }
+                peg$currPos = s3;
+                s3 = peg$FAILED;
               }
-              if (s2 === peg$FAILED) {
-                if (input.substr(peg$currPos, 2) === peg$c118) {
-                  s2 = peg$c118;
-                  peg$currPos += 2;
-                } else {
+            } else {
+              peg$currPos = s3;
+              s3 = peg$FAILED;
+            }
+          } else {
+            peg$currPos = s3;
+            s3 = peg$FAILED;
+          }
+        } else {
+          peg$currPos = s3;
+          s3 = peg$FAILED;
+        }
+        while (s3 !== peg$FAILED) {
+          s2.push(s3);
+          s3 = peg$currPos;
+          s4 = [];
+          s5 = peg$parsespaceNL();
+          while (s5 !== peg$FAILED) {
+            s4.push(s5);
+            s5 = peg$parsespaceNL();
+          }
+          if (s4 !== peg$FAILED) {
+            if (input.charCodeAt(peg$currPos) === 44) {
+              s5 = peg$c183;
+              peg$currPos++;
+            } else {
+              s5 = peg$FAILED;
+              if (peg$silentFails === 0) { peg$fail(peg$c184); }
+            }
+            if (s5 !== peg$FAILED) {
+              s6 = [];
+              s7 = peg$parsespaceNL();
+              while (s7 !== peg$FAILED) {
+                s6.push(s7);
+                s7 = peg$parsespaceNL();
+              }
+              if (s6 !== peg$FAILED) {
+                s7 = peg$parseaAssign();
+                if (s7 !== peg$FAILED) {
+                  peg$savedPos = s3;
+                  s4 = peg$c185(s1, s7);
+                  s3 = s4;
+                } else {
+                  peg$currPos = s3;
+                  s3 = peg$FAILED;
+                }
+              } else {
+                peg$currPos = s3;
+                s3 = peg$FAILED;
+              }
+            } else {
+              peg$currPos = s3;
+              s3 = peg$FAILED;
+            }
+          } else {
+            peg$currPos = s3;
+            s3 = peg$FAILED;
+          }
+        }
+        if (s2 !== peg$FAILED) {
+          peg$savedPos = s0;
+          s1 = peg$c186(s1, s2);
+          s0 = s1;
+        } else {
+          peg$currPos = s0;
+          s0 = peg$FAILED;
+        }
+      } else {
+        peg$currPos = s0;
+        s0 = peg$FAILED;
+      }
+      peg$silentFails--;
+      if (s0 === peg$FAILED) {
+        s1 = peg$FAILED;
+        if (peg$silentFails === 0) { peg$fail(peg$c182); }
+      }
+
+      return s0;
+    }
+
+    function peg$parseaAssign() {
+      var s0, s1, s2, s3, s4, s5, s6;
+
+      peg$silentFails++;
+      s0 = peg$currPos;
+      s1 = peg$parseaCond();
+      if (s1 !== peg$FAILED) {
+        s2 = [];
+        s3 = peg$parsespaceNL();
+        while (s3 !== peg$FAILED) {
+          s2.push(s3);
+          s3 = peg$parsespaceNL();
+        }
+        if (s2 !== peg$FAILED) {
+          s3 = peg$currPos;
+          if (input.charCodeAt(peg$currPos) === 61) {
+            s4 = peg$c72;
+            peg$currPos++;
+          } else {
+            s4 = peg$FAILED;
+            if (peg$silentFails === 0) { peg$fail(peg$c73); }
+          }
+          if (s4 !== peg$FAILED) {
+            s5 = peg$currPos;
+            peg$silentFails++;
+            if (input.charCodeAt(peg$currPos) === 61) {
+              s6 = peg$c72;
+              peg$currPos++;
+            } else {
+              s6 = peg$FAILED;
+              if (peg$silentFails === 0) { peg$fail(peg$c73); }
+            }
+            peg$silentFails--;
+            if (s6 === peg$FAILED) {
+              s5 = void 0;
+            } else {
+              peg$currPos = s5;
+              s5 = peg$FAILED;
+            }
+            if (s5 !== peg$FAILED) {
+              s4 = [s4, s5];
+              s3 = s4;
+            } else {
+              peg$currPos = s3;
+              s3 = peg$FAILED;
+            }
+          } else {
+            peg$currPos = s3;
+            s3 = peg$FAILED;
+          }
+          if (s3 === peg$FAILED) {
+            if (input.substr(peg$currPos, 2) === peg$c188) {
+              s3 = peg$c188;
+              peg$currPos += 2;
+            } else {
+              s3 = peg$FAILED;
+              if (peg$silentFails === 0) { peg$fail(peg$c189); }
+            }
+            if (s3 === peg$FAILED) {
+              if (input.substr(peg$currPos, 2) === peg$c190) {
+                s3 = peg$c190;
+                peg$currPos += 2;
+              } else {
+                s3 = peg$FAILED;
+                if (peg$silentFails === 0) { peg$fail(peg$c191); }
+              }
+              if (s3 === peg$FAILED) {
+                if (input.substr(peg$currPos, 2) === peg$c192) {
+                  s3 = peg$c192;
+                  peg$currPos += 2;
+                } else {
+                  s3 = peg$FAILED;
+                  if (peg$silentFails === 0) { peg$fail(peg$c193); }
+                }
+                if (s3 === peg$FAILED) {
+                  if (input.substr(peg$currPos, 2) === peg$c194) {
+                    s3 = peg$c194;
+                    peg$currPos += 2;
+                  } else {
+                    s3 = peg$FAILED;
+                    if (peg$silentFails === 0) { peg$fail(peg$c195); }
+                  }
+                  if (s3 === peg$FAILED) {
+                    if (input.substr(peg$currPos, 2) === peg$c196) {
+                      s3 = peg$c196;
+                      peg$currPos += 2;
+                    } else {
+                      s3 = peg$FAILED;
+                      if (peg$silentFails === 0) { peg$fail(peg$c197); }
+                    }
+                    if (s3 === peg$FAILED) {
+                      if (input.substr(peg$currPos, 3) === peg$c198) {
+                        s3 = peg$c198;
+                        peg$currPos += 3;
+                      } else {
+                        s3 = peg$FAILED;
+                        if (peg$silentFails === 0) { peg$fail(peg$c199); }
+                      }
+                      if (s3 === peg$FAILED) {
+                        if (input.substr(peg$currPos, 3) === peg$c200) {
+                          s3 = peg$c200;
+                          peg$currPos += 3;
+                        } else {
+                          s3 = peg$FAILED;
+                          if (peg$silentFails === 0) { peg$fail(peg$c201); }
+                        }
+                        if (s3 === peg$FAILED) {
+                          if (input.substr(peg$currPos, 2) === peg$c202) {
+                            s3 = peg$c202;
+                            peg$currPos += 2;
+                          } else {
+                            s3 = peg$FAILED;
+                            if (peg$silentFails === 0) { peg$fail(peg$c203); }
+                          }
+                          if (s3 === peg$FAILED) {
+                            if (input.substr(peg$currPos, 2) === peg$c204) {
+                              s3 = peg$c204;
+                              peg$currPos += 2;
+                            } else {
+                              s3 = peg$FAILED;
+                              if (peg$silentFails === 0) { peg$fail(peg$c205); }
+                            }
+                            if (s3 === peg$FAILED) {
+                              if (input.substr(peg$currPos, 2) === peg$c206) {
+                                s3 = peg$c206;
+                                peg$currPos += 2;
+                              } else {
+                                s3 = peg$FAILED;
+                                if (peg$silentFails === 0) { peg$fail(peg$c207); }
+                              }
+                            }
+                          }
+                        }
+                      }
+                    }
+                  }
+                }
+              }
+            }
+          }
+          if (s3 !== peg$FAILED) {
+            s4 = [];
+            s5 = peg$parsespaceNL();
+            while (s5 !== peg$FAILED) {
+              s4.push(s5);
+              s5 = peg$parsespaceNL();
+            }
+            if (s4 !== peg$FAILED) {
+              s5 = peg$parseaAssign();
+              if (s5 !== peg$FAILED) {
+                peg$savedPos = s0;
+                s1 = peg$c208(s1, s3, s5);
+                s0 = s1;
+              } else {
+                peg$currPos = s0;
+                s0 = peg$FAILED;
+              }
+            } else {
+              peg$currPos = s0;
+              s0 = peg$FAILED;
+            }
+          } else {
+            peg$currPos = s0;
+            s0 = peg$FAILED;
+          }
+        } else {
+          peg$currPos = s0;
+          s0 = peg$FAILED;
+        }
+      } else {
+        peg$currPos = s0;
+        s0 = peg$FAILED;
+      }
+      if (s0 === peg$FAILED) {
+        s0 = peg$currPos;
+        s1 = peg$parseaCond();
+        if (s1 !== peg$FAILED) {
+          peg$savedPos = s0;
+          s1 = peg$c209(s1);
+        }
+        s0 = s1;
+      }
+      peg$silentFails--;
+      if (s0 === peg$FAILED) {
+        s1 = peg$FAILED;
+        if (peg$silentFails === 0) { peg$fail(peg$c187); }
+      }
+
+      return s0;
+    }
+
+    function peg$parseaCond() {
+      var s0, s1, s2, s3, s4, s5, s6, s7, s8, s9;
+
+      peg$silentFails++;
+      s0 = peg$currPos;
+      s1 = peg$parseaLogicalOr();
+      if (s1 !== peg$FAILED) {
+        s2 = [];
+        s3 = peg$parsespaceNL();
+        while (s3 !== peg$FAILED) {
+          s2.push(s3);
+          s3 = peg$parsespaceNL();
+        }
+        if (s2 !== peg$FAILED) {
+          if (input.charCodeAt(peg$currPos) === 63) {
+            s3 = peg$c96;
+            peg$currPos++;
+          } else {
+            s3 = peg$FAILED;
+            if (peg$silentFails === 0) { peg$fail(peg$c97); }
+          }
+          if (s3 !== peg$FAILED) {
+            s4 = [];
+            s5 = peg$parsespaceNL();
+            while (s5 !== peg$FAILED) {
+              s4.push(s5);
+              s5 = peg$parsespaceNL();
+            }
+            if (s4 !== peg$FAILED) {
+              s5 = peg$parseaAssign();
+              if (s5 !== peg$FAILED) {
+                s6 = [];
+                s7 = peg$parsespaceNL();
+                while (s7 !== peg$FAILED) {
+                  s6.push(s7);
+                  s7 = peg$parsespaceNL();
+                }
+                if (s6 !== peg$FAILED) {
+                  if (input.charCodeAt(peg$currPos) === 58) {
+                    s7 = peg$c211;
+                    peg$currPos++;
+                  } else {
+                    s7 = peg$FAILED;
+                    if (peg$silentFails === 0) { peg$fail(peg$c212); }
+                  }
+                  if (s7 !== peg$FAILED) {
+                    s8 = [];
+                    s9 = peg$parsespaceNL();
+                    while (s9 !== peg$FAILED) {
+                      s8.push(s9);
+                      s9 = peg$parsespaceNL();
+                    }
+                    if (s8 !== peg$FAILED) {
+                      s9 = peg$parseaAssign();
+                      if (s9 !== peg$FAILED) {
+                        peg$savedPos = s0;
+                        s1 = peg$c213(s1, s5, s9);
+                        s0 = s1;
+                      } else {
+                        peg$currPos = s0;
+                        s0 = peg$FAILED;
+                      }
+                    } else {
+                      peg$currPos = s0;
+                      s0 = peg$FAILED;
+                    }
+                  } else {
+                    peg$currPos = s0;
+                    s0 = peg$FAILED;
+                  }
+                } else {
+                  peg$currPos = s0;
+                  s0 = peg$FAILED;
+                }
+              } else {
+                peg$currPos = s0;
+                s0 = peg$FAILED;
+              }
+            } else {
+              peg$currPos = s0;
+              s0 = peg$FAILED;
+            }
+          } else {
+            peg$currPos = s0;
+            s0 = peg$FAILED;
+          }
+        } else {
+          peg$currPos = s0;
+          s0 = peg$FAILED;
+        }
+      } else {
+        peg$currPos = s0;
+        s0 = peg$FAILED;
+      }
+      if (s0 === peg$FAILED) {
+        s0 = peg$currPos;
+        s1 = peg$parseaLogicalOr();
+        if (s1 !== peg$FAILED) {
+          peg$savedPos = s0;
+          s1 = peg$c209(s1);
+        }
+        s0 = s1;
+      }
+      peg$silentFails--;
+      if (s0 === peg$FAILED) {
+        s1 = peg$FAILED;
+        if (peg$silentFails === 0) { peg$fail(peg$c210); }
+      }
+
+      return s0;
+    }
+
+    function peg$parseaLogicalOr() {
+      var s0, s1, s2, s3, s4, s5, s6, s7;
+
+      peg$silentFails++;
+      s0 = peg$currPos;
+      s1 = peg$parseaLogicalAnd();
+      if (s1 !== peg$FAILED) {
+        s2 = [];
+        s3 = peg$currPos;
+        s4 = [];
+        s5 = peg$parsespaceNL();
+        while (s5 !== peg$FAILED) {
+          s4.push(s5);
+          s5 = peg$parsespaceNL();
+        }
+        if (s4 !== peg$FAILED) {
+          if (input.substr(peg$currPos, 2) === peg$c5) {
+            s5 = peg$c5;
+            peg$currPos += 2;
+          } else {
+            s5 = peg$FAILED;
+            if (peg$silentFails === 0) { peg$fail(peg$c6); }
+          }
+          if (s5 !== peg$FAILED) {
+            s6 = [];
+            s7 = peg$parsespaceNL();
+            while (s7 !== peg$FAILED) {
+              s6.push(s7);
+              s7 = peg$parsespaceNL();
+            }
+            if (s6 !== peg$FAILED) {
+              s7 = peg$parseaLogicalAnd();
+              if (s7 !== peg$FAILED) {
+                peg$savedPos = s3;
+                s4 = peg$c215(s1, s5, s7);
+                s3 = s4;
+              } else {
+                peg$currPos = s3;
+                s3 = peg$FAILED;
+              }
+            } else {
+              peg$currPos = s3;
+              s3 = peg$FAILED;
+            }
+          } else {
+            peg$currPos = s3;
+            s3 = peg$FAILED;
+          }
+        } else {
+          peg$currPos = s3;
+          s3 = peg$FAILED;
+        }
+        while (s3 !== peg$FAILED) {
+          s2.push(s3);
+          s3 = peg$currPos;
+          s4 = [];
+          s5 = peg$parsespaceNL();
+          while (s5 !== peg$FAILED) {
+            s4.push(s5);
+            s5 = peg$parsespaceNL();
+          }
+          if (s4 !== peg$FAILED) {
+            if (input.substr(peg$currPos, 2) === peg$c5) {
+              s5 = peg$c5;
+              peg$currPos += 2;
+            } else {
+              s5 = peg$FAILED;
+              if (peg$silentFails === 0) { peg$fail(peg$c6); }
+            }
+            if (s5 !== peg$FAILED) {
+              s6 = [];
+              s7 = peg$parsespaceNL();
+              while (s7 !== peg$FAILED) {
+                s6.push(s7);
+                s7 = peg$parsespaceNL();
+              }
+              if (s6 !== peg$FAILED) {
+                s7 = peg$parseaLogicalAnd();
+                if (s7 !== peg$FAILED) {
+                  peg$savedPos = s3;
+                  s4 = peg$c215(s1, s5, s7);
+                  s3 = s4;
+                } else {
+                  peg$currPos = s3;
+                  s3 = peg$FAILED;
+                }
+              } else {
+                peg$currPos = s3;
+                s3 = peg$FAILED;
+              }
+            } else {
+              peg$currPos = s3;
+              s3 = peg$FAILED;
+            }
+          } else {
+            peg$currPos = s3;
+            s3 = peg$FAILED;
+          }
+        }
+        if (s2 !== peg$FAILED) {
+          peg$savedPos = s0;
+          s1 = peg$c216(s1, s2);
+          s0 = s1;
+        } else {
+          peg$currPos = s0;
+          s0 = peg$FAILED;
+        }
+      } else {
+        peg$currPos = s0;
+        s0 = peg$FAILED;
+      }
+      peg$silentFails--;
+      if (s0 === peg$FAILED) {
+        s1 = peg$FAILED;
+        if (peg$silentFails === 0) { peg$fail(peg$c214); }
+      }
+
+      return s0;
+    }
+
+    function peg$parseaLogicalAnd() {
+      var s0, s1, s2, s3, s4, s5, s6, s7;
+
+      peg$silentFails++;
+      s0 = peg$currPos;
+      s1 = peg$parseaBitwiseOr();
+      if (s1 !== peg$FAILED) {
+        s2 = [];
+        s3 = peg$currPos;
+        s4 = [];
+        s5 = peg$parsespaceNL();
+        while (s5 !== peg$FAILED) {
+          s4.push(s5);
+          s5 = peg$parsespaceNL();
+        }
+        if (s4 !== peg$FAILED) {
+          if (input.substr(peg$currPos, 2) === peg$c3) {
+            s5 = peg$c3;
+            peg$currPos += 2;
+          } else {
+            s5 = peg$FAILED;
+            if (peg$silentFails === 0) { peg$fail(peg$c4); }
+          }
+          if (s5 !== peg$FAILED) {
+            s6 = [];
+            s7 = peg$parsespaceNL();
+            while (s7 !== peg$FAILED) {
+              s6.push(s7);
+              s7 = peg$parsespaceNL();
+            }
+            if (s6 !== peg$FAILED) {
+              s7 = peg$parseaBitwiseOr();
+              if (s7 !== peg$FAILED) {
+                peg$savedPos = s3;
+                s4 = peg$c215(s1, s5, s7);
+                s3 = s4;
+              } else {
+                peg$currPos = s3;
+                s3 = peg$FAILED;
+              }
+            } else {
+              peg$currPos = s3;
+              s3 = peg$FAILED;
+            }
+          } else {
+            peg$currPos = s3;
+            s3 = peg$FAILED;
+          }
+        } else {
+          peg$currPos = s3;
+          s3 = peg$FAILED;
+        }
+        while (s3 !== peg$FAILED) {
+          s2.push(s3);
+          s3 = peg$currPos;
+          s4 = [];
+          s5 = peg$parsespaceNL();
+          while (s5 !== peg$FAILED) {
+            s4.push(s5);
+            s5 = peg$parsespaceNL();
+          }
+          if (s4 !== peg$FAILED) {
+            if (input.substr(peg$currPos, 2) === peg$c3) {
+              s5 = peg$c3;
+              peg$currPos += 2;
+            } else {
+              s5 = peg$FAILED;
+              if (peg$silentFails === 0) { peg$fail(peg$c4); }
+            }
+            if (s5 !== peg$FAILED) {
+              s6 = [];
+              s7 = peg$parsespaceNL();
+              while (s7 !== peg$FAILED) {
+                s6.push(s7);
+                s7 = peg$parsespaceNL();
+              }
+              if (s6 !== peg$FAILED) {
+                s7 = peg$parseaBitwiseOr();
+                if (s7 !== peg$FAILED) {
+                  peg$savedPos = s3;
+                  s4 = peg$c215(s1, s5, s7);
+                  s3 = s4;
+                } else {
+                  peg$currPos = s3;
+                  s3 = peg$FAILED;
+                }
+              } else {
+                peg$currPos = s3;
+                s3 = peg$FAILED;
+              }
+            } else {
+              peg$currPos = s3;
+              s3 = peg$FAILED;
+            }
+          } else {
+            peg$currPos = s3;
+            s3 = peg$FAILED;
+          }
+        }
+        if (s2 !== peg$FAILED) {
+          peg$savedPos = s0;
+          s1 = peg$c216(s1, s2);
+          s0 = s1;
+        } else {
+          peg$currPos = s0;
+          s0 = peg$FAILED;
+        }
+      } else {
+        peg$currPos = s0;
+        s0 = peg$FAILED;
+      }
+      peg$silentFails--;
+      if (s0 === peg$FAILED) {
+        s1 = peg$FAILED;
+        if (peg$silentFails === 0) { peg$fail(peg$c217); }
+      }
+
+      return s0;
+    }
+
+    function peg$parseaBitwiseOr() {
+      var s0, s1, s2, s3, s4, s5, s6, s7, s8;
+
+      s0 = peg$currPos;
+      s1 = peg$parseaBitwiseXor();
+      if (s1 !== peg$FAILED) {
+        s2 = [];
+        s3 = peg$currPos;
+        s4 = [];
+        s5 = peg$parsespaceNL();
+        while (s5 !== peg$FAILED) {
+          s4.push(s5);
+          s5 = peg$parsespaceNL();
+        }
+        if (s4 !== peg$FAILED) {
+          if (input.charCodeAt(peg$currPos) === 124) {
+            s5 = peg$c167;
+            peg$currPos++;
+          } else {
+            s5 = peg$FAILED;
+            if (peg$silentFails === 0) { peg$fail(peg$c168); }
+          }
+          if (s5 !== peg$FAILED) {
+            s6 = peg$currPos;
+            peg$silentFails++;
+            if (peg$c218.test(input.charAt(peg$currPos))) {
+              s7 = input.charAt(peg$currPos);
+              peg$currPos++;
+            } else {
+              s7 = peg$FAILED;
+              if (peg$silentFails === 0) { peg$fail(peg$c219); }
+            }
+            peg$silentFails--;
+            if (s7 === peg$FAILED) {
+              s6 = void 0;
+            } else {
+              peg$currPos = s6;
+              s6 = peg$FAILED;
+            }
+            if (s6 !== peg$FAILED) {
+              s7 = [];
+              s8 = peg$parsespaceNL();
+              while (s8 !== peg$FAILED) {
+                s7.push(s8);
+                s8 = peg$parsespaceNL();
+              }
+              if (s7 !== peg$FAILED) {
+                s8 = peg$parseaBitwiseXor();
+                if (s8 !== peg$FAILED) {
+                  peg$savedPos = s3;
+                  s4 = peg$c215(s1, s5, s8);
+                  s3 = s4;
+                } else {
+                  peg$currPos = s3;
+                  s3 = peg$FAILED;
+                }
+              } else {
+                peg$currPos = s3;
+                s3 = peg$FAILED;
+              }
+            } else {
+              peg$currPos = s3;
+              s3 = peg$FAILED;
+            }
+          } else {
+            peg$currPos = s3;
+            s3 = peg$FAILED;
+          }
+        } else {
+          peg$currPos = s3;
+          s3 = peg$FAILED;
+        }
+        while (s3 !== peg$FAILED) {
+          s2.push(s3);
+          s3 = peg$currPos;
+          s4 = [];
+          s5 = peg$parsespaceNL();
+          while (s5 !== peg$FAILED) {
+            s4.push(s5);
+            s5 = peg$parsespaceNL();
+          }
+          if (s4 !== peg$FAILED) {
+            if (input.charCodeAt(peg$currPos) === 124) {
+              s5 = peg$c167;
+              peg$currPos++;
+            } else {
+              s5 = peg$FAILED;
+              if (peg$silentFails === 0) { peg$fail(peg$c168); }
+            }
+            if (s5 !== peg$FAILED) {
+              s6 = peg$currPos;
+              peg$silentFails++;
+              if (peg$c218.test(input.charAt(peg$currPos))) {
+                s7 = input.charAt(peg$currPos);
+                peg$currPos++;
+              } else {
+                s7 = peg$FAILED;
+                if (peg$silentFails === 0) { peg$fail(peg$c219); }
+              }
+              peg$silentFails--;
+              if (s7 === peg$FAILED) {
+                s6 = void 0;
+              } else {
+                peg$currPos = s6;
+                s6 = peg$FAILED;
+              }
+              if (s6 !== peg$FAILED) {
+                s7 = [];
+                s8 = peg$parsespaceNL();
+                while (s8 !== peg$FAILED) {
+                  s7.push(s8);
+                  s8 = peg$parsespaceNL();
+                }
+                if (s7 !== peg$FAILED) {
+                  s8 = peg$parseaBitwiseXor();
+                  if (s8 !== peg$FAILED) {
+                    peg$savedPos = s3;
+                    s4 = peg$c215(s1, s5, s8);
+                    s3 = s4;
+                  } else {
+                    peg$currPos = s3;
+                    s3 = peg$FAILED;
+                  }
+                } else {
+                  peg$currPos = s3;
+                  s3 = peg$FAILED;
+                }
+              } else {
+                peg$currPos = s3;
+                s3 = peg$FAILED;
+              }
+            } else {
+              peg$currPos = s3;
+              s3 = peg$FAILED;
+            }
+          } else {
+            peg$currPos = s3;
+            s3 = peg$FAILED;
+          }
+        }
+        if (s2 !== peg$FAILED) {
+          peg$savedPos = s0;
+          s1 = peg$c220(s1, s2);
+          s0 = s1;
+        } else {
+          peg$currPos = s0;
+          s0 = peg$FAILED;
+        }
+      } else {
+        peg$currPos = s0;
+        s0 = peg$FAILED;
+      }
+
+      return s0;
+    }
+
+    function peg$parseaBitwiseXor() {
+      var s0, s1, s2, s3, s4, s5, s6, s7, s8;
+
+      s0 = peg$currPos;
+      s1 = peg$parseaBitwiseAnd();
+      if (s1 !== peg$FAILED) {
+        s2 = [];
+        s3 = peg$currPos;
+        s4 = [];
+        s5 = peg$parsespaceNL();
+        while (s5 !== peg$FAILED) {
+          s4.push(s5);
+          s5 = peg$parsespaceNL();
+        }
+        if (s4 !== peg$FAILED) {
+          if (input.charCodeAt(peg$currPos) === 94) {
+            s5 = peg$c221;
+            peg$currPos++;
+          } else {
+            s5 = peg$FAILED;
+            if (peg$silentFails === 0) { peg$fail(peg$c222); }
+          }
+          if (s5 !== peg$FAILED) {
+            s6 = peg$currPos;
+            peg$silentFails++;
+            if (input.charCodeAt(peg$currPos) === 61) {
+              s7 = peg$c72;
+              peg$currPos++;
+            } else {
+              s7 = peg$FAILED;
+              if (peg$silentFails === 0) { peg$fail(peg$c73); }
+            }
+            peg$silentFails--;
+            if (s7 === peg$FAILED) {
+              s6 = void 0;
+            } else {
+              peg$currPos = s6;
+              s6 = peg$FAILED;
+            }
+            if (s6 !== peg$FAILED) {
+              s7 = [];
+              s8 = peg$parsespaceNL();
+              while (s8 !== peg$FAILED) {
+                s7.push(s8);
+                s8 = peg$parsespaceNL();
+              }
+              if (s7 !== peg$FAILED) {
+                s8 = peg$parseaBitwiseAnd();
+                if (s8 !== peg$FAILED) {
+                  peg$savedPos = s3;
+                  s4 = peg$c215(s1, s5, s8);
+                  s3 = s4;
+                } else {
+                  peg$currPos = s3;
+                  s3 = peg$FAILED;
+                }
+              } else {
+                peg$currPos = s3;
+                s3 = peg$FAILED;
+              }
+            } else {
+              peg$currPos = s3;
+              s3 = peg$FAILED;
+            }
+          } else {
+            peg$currPos = s3;
+            s3 = peg$FAILED;
+          }
+        } else {
+          peg$currPos = s3;
+          s3 = peg$FAILED;
+        }
+        while (s3 !== peg$FAILED) {
+          s2.push(s3);
+          s3 = peg$currPos;
+          s4 = [];
+          s5 = peg$parsespaceNL();
+          while (s5 !== peg$FAILED) {
+            s4.push(s5);
+            s5 = peg$parsespaceNL();
+          }
+          if (s4 !== peg$FAILED) {
+            if (input.charCodeAt(peg$currPos) === 94) {
+              s5 = peg$c221;
+              peg$currPos++;
+            } else {
+              s5 = peg$FAILED;
+              if (peg$silentFails === 0) { peg$fail(peg$c222); }
+            }
+            if (s5 !== peg$FAILED) {
+              s6 = peg$currPos;
+              peg$silentFails++;
+              if (input.charCodeAt(peg$currPos) === 61) {
+                s7 = peg$c72;
+                peg$currPos++;
+              } else {
+                s7 = peg$FAILED;
+                if (peg$silentFails === 0) { peg$fail(peg$c73); }
+              }
+              peg$silentFails--;
+              if (s7 === peg$FAILED) {
+                s6 = void 0;
+              } else {
+                peg$currPos = s6;
+                s6 = peg$FAILED;
+              }
+              if (s6 !== peg$FAILED) {
+                s7 = [];
+                s8 = peg$parsespaceNL();
+                while (s8 !== peg$FAILED) {
+                  s7.push(s8);
+                  s8 = peg$parsespaceNL();
+                }
+                if (s7 !== peg$FAILED) {
+                  s8 = peg$parseaBitwiseAnd();
+                  if (s8 !== peg$FAILED) {
+                    peg$savedPos = s3;
+                    s4 = peg$c215(s1, s5, s8);
+                    s3 = s4;
+                  } else {
+                    peg$currPos = s3;
+                    s3 = peg$FAILED;
+                  }
+                } else {
+                  peg$currPos = s3;
+                  s3 = peg$FAILED;
+                }
+              } else {
+                peg$currPos = s3;
+                s3 = peg$FAILED;
+              }
+            } else {
+              peg$currPos = s3;
+              s3 = peg$FAILED;
+            }
+          } else {
+            peg$currPos = s3;
+            s3 = peg$FAILED;
+          }
+        }
+        if (s2 !== peg$FAILED) {
+          peg$savedPos = s0;
+          s1 = peg$c220(s1, s2);
+          s0 = s1;
+        } else {
+          peg$currPos = s0;
+          s0 = peg$FAILED;
+        }
+      } else {
+        peg$currPos = s0;
+        s0 = peg$FAILED;
+      }
+
+      return s0;
+    }
+
+    function peg$parseaBitwiseAnd() {
+      var s0, s1, s2, s3, s4, s5, s6, s7, s8;
+
+      s0 = peg$currPos;
+      s1 = peg$parseaEquality();
+      if (s1 !== peg$FAILED) {
+        s2 = [];
+        s3 = peg$currPos;
+        s4 = [];
+        s5 = peg$parsespaceNL();
+        while (s5 !== peg$FAILED) {
+          s4.push(s5);
+          s5 = peg$parsespaceNL();
+        }
+        if (s4 !== peg$FAILED) {
+          if (input.charCodeAt(peg$currPos) === 38) {
+            s5 = peg$c164;
+            peg$currPos++;
+          } else {
+            s5 = peg$FAILED;
+            if (peg$silentFails === 0) { peg$fail(peg$c165); }
+          }
+          if (s5 !== peg$FAILED) {
+            s6 = peg$currPos;
+            peg$silentFails++;
+            if (peg$c223.test(input.charAt(peg$currPos))) {
+              s7 = input.charAt(peg$currPos);
+              peg$currPos++;
+            } else {
+              s7 = peg$FAILED;
+              if (peg$silentFails === 0) { peg$fail(peg$c224); }
+            }
+            peg$silentFails--;
+            if (s7 === peg$FAILED) {
+              s6 = void 0;
+            } else {
+              peg$currPos = s6;
+              s6 = peg$FAILED;
+            }
+            if (s6 !== peg$FAILED) {
+              s7 = [];
+              s8 = peg$parsespaceNL();
+              while (s8 !== peg$FAILED) {
+                s7.push(s8);
+                s8 = peg$parsespaceNL();
+              }
+              if (s7 !== peg$FAILED) {
+                s8 = peg$parseaEquality();
+                if (s8 !== peg$FAILED) {
+                  peg$savedPos = s3;
+                  s4 = peg$c215(s1, s5, s8);
+                  s3 = s4;
+                } else {
+                  peg$currPos = s3;
+                  s3 = peg$FAILED;
+                }
+              } else {
+                peg$currPos = s3;
+                s3 = peg$FAILED;
+              }
+            } else {
+              peg$currPos = s3;
+              s3 = peg$FAILED;
+            }
+          } else {
+            peg$currPos = s3;
+            s3 = peg$FAILED;
+          }
+        } else {
+          peg$currPos = s3;
+          s3 = peg$FAILED;
+        }
+        while (s3 !== peg$FAILED) {
+          s2.push(s3);
+          s3 = peg$currPos;
+          s4 = [];
+          s5 = peg$parsespaceNL();
+          while (s5 !== peg$FAILED) {
+            s4.push(s5);
+            s5 = peg$parsespaceNL();
+          }
+          if (s4 !== peg$FAILED) {
+            if (input.charCodeAt(peg$currPos) === 38) {
+              s5 = peg$c164;
+              peg$currPos++;
+            } else {
+              s5 = peg$FAILED;
+              if (peg$silentFails === 0) { peg$fail(peg$c165); }
+            }
+            if (s5 !== peg$FAILED) {
+              s6 = peg$currPos;
+              peg$silentFails++;
+              if (peg$c223.test(input.charAt(peg$currPos))) {
+                s7 = input.charAt(peg$currPos);
+                peg$currPos++;
+              } else {
+                s7 = peg$FAILED;
+                if (peg$silentFails === 0) { peg$fail(peg$c224); }
+              }
+              peg$silentFails--;
+              if (s7 === peg$FAILED) {
+                s6 = void 0;
+              } else {
+                peg$currPos = s6;
+                s6 = peg$FAILED;
+              }
+              if (s6 !== peg$FAILED) {
+                s7 = [];
+                s8 = peg$parsespaceNL();
+                while (s8 !== peg$FAILED) {
+                  s7.push(s8);
+                  s8 = peg$parsespaceNL();
+                }
+                if (s7 !== peg$FAILED) {
+                  s8 = peg$parseaEquality();
+                  if (s8 !== peg$FAILED) {
+                    peg$savedPos = s3;
+                    s4 = peg$c215(s1, s5, s8);
+                    s3 = s4;
+                  } else {
+                    peg$currPos = s3;
+                    s3 = peg$FAILED;
+                  }
+                } else {
+                  peg$currPos = s3;
+                  s3 = peg$FAILED;
+                }
+              } else {
+                peg$currPos = s3;
+                s3 = peg$FAILED;
+              }
+            } else {
+              peg$currPos = s3;
+              s3 = peg$FAILED;
+            }
+          } else {
+            peg$currPos = s3;
+            s3 = peg$FAILED;
+          }
+        }
+        if (s2 !== peg$FAILED) {
+          peg$savedPos = s0;
+          s1 = peg$c220(s1, s2);
+          s0 = s1;
+        } else {
+          peg$currPos = s0;
+          s0 = peg$FAILED;
+        }
+      } else {
+        peg$currPos = s0;
+        s0 = peg$FAILED;
+      }
+
+      return s0;
+    }
+
+    function peg$parseaEquality() {
+      var s0, s1, s2, s3, s4, s5, s6, s7;
+
+      s0 = peg$currPos;
+      s1 = peg$parseaComparison();
+      if (s1 !== peg$FAILED) {
+        s2 = [];
+        s3 = peg$currPos;
+        s4 = [];
+        s5 = peg$parsespaceNL();
+        while (s5 !== peg$FAILED) {
+          s4.push(s5);
+          s5 = peg$parsespaceNL();
+        }
+        if (s4 !== peg$FAILED) {
+          if (input.substr(peg$currPos, 2) === peg$c225) {
+            s5 = peg$c225;
+            peg$currPos += 2;
+          } else {
+            s5 = peg$FAILED;
+            if (peg$silentFails === 0) { peg$fail(peg$c226); }
+          }
+          if (s5 === peg$FAILED) {
+            if (input.substr(peg$currPos, 2) === peg$c227) {
+              s5 = peg$c227;
+              peg$currPos += 2;
+            } else {
+              s5 = peg$FAILED;
+              if (peg$silentFails === 0) { peg$fail(peg$c228); }
+            }
+          }
+          if (s5 !== peg$FAILED) {
+            s6 = [];
+            s7 = peg$parsespaceNL();
+            while (s7 !== peg$FAILED) {
+              s6.push(s7);
+              s7 = peg$parsespaceNL();
+            }
+            if (s6 !== peg$FAILED) {
+              s7 = peg$parseaComparison();
+              if (s7 !== peg$FAILED) {
+                peg$savedPos = s3;
+                s4 = peg$c215(s1, s5, s7);
+                s3 = s4;
+              } else {
+                peg$currPos = s3;
+                s3 = peg$FAILED;
+              }
+            } else {
+              peg$currPos = s3;
+              s3 = peg$FAILED;
+            }
+          } else {
+            peg$currPos = s3;
+            s3 = peg$FAILED;
+          }
+        } else {
+          peg$currPos = s3;
+          s3 = peg$FAILED;
+        }
+        while (s3 !== peg$FAILED) {
+          s2.push(s3);
+          s3 = peg$currPos;
+          s4 = [];
+          s5 = peg$parsespaceNL();
+          while (s5 !== peg$FAILED) {
+            s4.push(s5);
+            s5 = peg$parsespaceNL();
+          }
+          if (s4 !== peg$FAILED) {
+            if (input.substr(peg$currPos, 2) === peg$c225) {
+              s5 = peg$c225;
+              peg$currPos += 2;
+            } else {
+              s5 = peg$FAILED;
+              if (peg$silentFails === 0) { peg$fail(peg$c226); }
+            }
+            if (s5 === peg$FAILED) {
+              if (input.substr(peg$currPos, 2) === peg$c227) {
+                s5 = peg$c227;
+                peg$currPos += 2;
+              } else {
+                s5 = peg$FAILED;
+                if (peg$silentFails === 0) { peg$fail(peg$c228); }
+              }
+            }
+            if (s5 !== peg$FAILED) {
+              s6 = [];
+              s7 = peg$parsespaceNL();
+              while (s7 !== peg$FAILED) {
+                s6.push(s7);
+                s7 = peg$parsespaceNL();
+              }
+              if (s6 !== peg$FAILED) {
+                s7 = peg$parseaComparison();
+                if (s7 !== peg$FAILED) {
+                  peg$savedPos = s3;
+                  s4 = peg$c215(s1, s5, s7);
+                  s3 = s4;
+                } else {
+                  peg$currPos = s3;
+                  s3 = peg$FAILED;
+                }
+              } else {
+                peg$currPos = s3;
+                s3 = peg$FAILED;
+              }
+            } else {
+              peg$currPos = s3;
+              s3 = peg$FAILED;
+            }
+          } else {
+            peg$currPos = s3;
+            s3 = peg$FAILED;
+          }
+        }
+        if (s2 !== peg$FAILED) {
+          peg$savedPos = s0;
+          s1 = peg$c220(s1, s2);
+          s0 = s1;
+        } else {
+          peg$currPos = s0;
+          s0 = peg$FAILED;
+        }
+      } else {
+        peg$currPos = s0;
+        s0 = peg$FAILED;
+      }
+
+      return s0;
+    }
+
+    function peg$parseaComparison() {
+      var s0, s1, s2, s3, s4, s5, s6, s7, s8;
+
+      s0 = peg$currPos;
+      s1 = peg$parseaBitwiseShift();
+      if (s1 !== peg$FAILED) {
+        s2 = [];
+        s3 = peg$currPos;
+        s4 = [];
+        s5 = peg$parsespaceNL();
+        while (s5 !== peg$FAILED) {
+          s4.push(s5);
+          s5 = peg$parsespaceNL();
+        }
+        if (s4 !== peg$FAILED) {
+          if (input.substr(peg$currPos, 2) === peg$c229) {
+            s5 = peg$c229;
+            peg$currPos += 2;
+          } else {
+            s5 = peg$FAILED;
+            if (peg$silentFails === 0) { peg$fail(peg$c230); }
+          }
+          if (s5 === peg$FAILED) {
+            if (input.substr(peg$currPos, 2) === peg$c231) {
+              s5 = peg$c231;
+              peg$currPos += 2;
+            } else {
+              s5 = peg$FAILED;
+              if (peg$silentFails === 0) { peg$fail(peg$c232); }
+            }
+            if (s5 === peg$FAILED) {
+              s5 = peg$currPos;
+              if (input.charCodeAt(peg$currPos) === 60) {
+                s6 = peg$c157;
+                peg$currPos++;
+              } else {
+                s6 = peg$FAILED;
+                if (peg$silentFails === 0) { peg$fail(peg$c158); }
+              }
+              if (s6 !== peg$FAILED) {
+                s7 = peg$currPos;
+                peg$silentFails++;
+                if (input.charCodeAt(peg$currPos) === 60) {
+                  s8 = peg$c157;
+                  peg$currPos++;
+                } else {
+                  s8 = peg$FAILED;
+                  if (peg$silentFails === 0) { peg$fail(peg$c158); }
+                }
+                peg$silentFails--;
+                if (s8 === peg$FAILED) {
+                  s7 = void 0;
+                } else {
+                  peg$currPos = s7;
+                  s7 = peg$FAILED;
+                }
+                if (s7 !== peg$FAILED) {
+                  peg$savedPos = s5;
+                  s6 = peg$c233(s1, s6);
+                  s5 = s6;
+                } else {
+                  peg$currPos = s5;
+                  s5 = peg$FAILED;
+                }
+              } else {
+                peg$currPos = s5;
+                s5 = peg$FAILED;
+              }
+              if (s5 === peg$FAILED) {
+                s5 = peg$currPos;
+                if (input.charCodeAt(peg$currPos) === 62) {
+                  s6 = peg$c159;
+                  peg$currPos++;
+                } else {
+                  s6 = peg$FAILED;
+                  if (peg$silentFails === 0) { peg$fail(peg$c160); }
+                }
+                if (s6 !== peg$FAILED) {
+                  s7 = peg$currPos;
+                  peg$silentFails++;
+                  if (input.charCodeAt(peg$currPos) === 62) {
+                    s8 = peg$c159;
+                    peg$currPos++;
+                  } else {
+                    s8 = peg$FAILED;
+                    if (peg$silentFails === 0) { peg$fail(peg$c160); }
+                  }
+                  peg$silentFails--;
+                  if (s8 === peg$FAILED) {
+                    s7 = void 0;
+                  } else {
+                    peg$currPos = s7;
+                    s7 = peg$FAILED;
+                  }
+                  if (s7 !== peg$FAILED) {
+                    peg$savedPos = s5;
+                    s6 = peg$c233(s1, s6);
+                    s5 = s6;
+                  } else {
+                    peg$currPos = s5;
+                    s5 = peg$FAILED;
+                  }
+                } else {
+                  peg$currPos = s5;
+                  s5 = peg$FAILED;
+                }
+              }
+            }
+          }
+          if (s5 !== peg$FAILED) {
+            s6 = [];
+            s7 = peg$parsespaceNL();
+            while (s7 !== peg$FAILED) {
+              s6.push(s7);
+              s7 = peg$parsespaceNL();
+            }
+            if (s6 !== peg$FAILED) {
+              s7 = peg$parseaBitwiseShift();
+              if (s7 !== peg$FAILED) {
+                peg$savedPos = s3;
+                s4 = peg$c215(s1, s5, s7);
+                s3 = s4;
+              } else {
+                peg$currPos = s3;
+                s3 = peg$FAILED;
+              }
+            } else {
+              peg$currPos = s3;
+              s3 = peg$FAILED;
+            }
+          } else {
+            peg$currPos = s3;
+            s3 = peg$FAILED;
+          }
+        } else {
+          peg$currPos = s3;
+          s3 = peg$FAILED;
+        }
+        while (s3 !== peg$FAILED) {
+          s2.push(s3);
+          s3 = peg$currPos;
+          s4 = [];
+          s5 = peg$parsespaceNL();
+          while (s5 !== peg$FAILED) {
+            s4.push(s5);
+            s5 = peg$parsespaceNL();
+          }
+          if (s4 !== peg$FAILED) {
+            if (input.substr(peg$currPos, 2) === peg$c229) {
+              s5 = peg$c229;
+              peg$currPos += 2;
+            } else {
+              s5 = peg$FAILED;
+              if (peg$silentFails === 0) { peg$fail(peg$c230); }
+            }
+            if (s5 === peg$FAILED) {
+              if (input.substr(peg$currPos, 2) === peg$c231) {
+                s5 = peg$c231;
+                peg$currPos += 2;
+              } else {
+                s5 = peg$FAILED;
+                if (peg$silentFails === 0) { peg$fail(peg$c232); }
+              }
+              if (s5 === peg$FAILED) {
+                s5 = peg$currPos;
+                if (input.charCodeAt(peg$currPos) === 60) {
+                  s6 = peg$c157;
+                  peg$currPos++;
+                } else {
+                  s6 = peg$FAILED;
+                  if (peg$silentFails === 0) { peg$fail(peg$c158); }
+                }
+                if (s6 !== peg$FAILED) {
+                  s7 = peg$currPos;
+                  peg$silentFails++;
+                  if (input.charCodeAt(peg$currPos) === 60) {
+                    s8 = peg$c157;
+                    peg$currPos++;
+                  } else {
+                    s8 = peg$FAILED;
+                    if (peg$silentFails === 0) { peg$fail(peg$c158); }
+                  }
+                  peg$silentFails--;
+                  if (s8 === peg$FAILED) {
+                    s7 = void 0;
+                  } else {
+                    peg$currPos = s7;
+                    s7 = peg$FAILED;
+                  }
+                  if (s7 !== peg$FAILED) {
+                    peg$savedPos = s5;
+                    s6 = peg$c233(s1, s6);
+                    s5 = s6;
+                  } else {
+                    peg$currPos = s5;
+                    s5 = peg$FAILED;
+                  }
+                } else {
+                  peg$currPos = s5;
+                  s5 = peg$FAILED;
+                }
+                if (s5 === peg$FAILED) {
+                  s5 = peg$currPos;
+                  if (input.charCodeAt(peg$currPos) === 62) {
+                    s6 = peg$c159;
+                    peg$currPos++;
+                  } else {
+                    s6 = peg$FAILED;
+                    if (peg$silentFails === 0) { peg$fail(peg$c160); }
+                  }
+                  if (s6 !== peg$FAILED) {
+                    s7 = peg$currPos;
+                    peg$silentFails++;
+                    if (input.charCodeAt(peg$currPos) === 62) {
+                      s8 = peg$c159;
+                      peg$currPos++;
+                    } else {
+                      s8 = peg$FAILED;
+                      if (peg$silentFails === 0) { peg$fail(peg$c160); }
+                    }
+                    peg$silentFails--;
+                    if (s8 === peg$FAILED) {
+                      s7 = void 0;
+                    } else {
+                      peg$currPos = s7;
+                      s7 = peg$FAILED;
+                    }
+                    if (s7 !== peg$FAILED) {
+                      peg$savedPos = s5;
+                      s6 = peg$c233(s1, s6);
+                      s5 = s6;
+                    } else {
+                      peg$currPos = s5;
+                      s5 = peg$FAILED;
+                    }
+                  } else {
+                    peg$currPos = s5;
+                    s5 = peg$FAILED;
+                  }
+                }
+              }
+            }
+            if (s5 !== peg$FAILED) {
+              s6 = [];
+              s7 = peg$parsespaceNL();
+              while (s7 !== peg$FAILED) {
+                s6.push(s7);
+                s7 = peg$parsespaceNL();
+              }
+              if (s6 !== peg$FAILED) {
+                s7 = peg$parseaBitwiseShift();
+                if (s7 !== peg$FAILED) {
+                  peg$savedPos = s3;
+                  s4 = peg$c215(s1, s5, s7);
+                  s3 = s4;
+                } else {
+                  peg$currPos = s3;
+                  s3 = peg$FAILED;
+                }
+              } else {
+                peg$currPos = s3;
+                s3 = peg$FAILED;
+              }
+            } else {
+              peg$currPos = s3;
+              s3 = peg$FAILED;
+            }
+          } else {
+            peg$currPos = s3;
+            s3 = peg$FAILED;
+          }
+        }
+        if (s2 !== peg$FAILED) {
+          peg$savedPos = s0;
+          s1 = peg$c220(s1, s2);
+          s0 = s1;
+        } else {
+          peg$currPos = s0;
+          s0 = peg$FAILED;
+        }
+      } else {
+        peg$currPos = s0;
+        s0 = peg$FAILED;
+      }
+
+      return s0;
+    }
+
+    function peg$parseaBitwiseShift() {
+      var s0, s1, s2, s3, s4, s5, s6, s7, s8;
+
+      s0 = peg$currPos;
+      s1 = peg$parseaAddSubtract();
+      if (s1 !== peg$FAILED) {
+        s2 = [];
+        s3 = peg$currPos;
+        s4 = [];
+        s5 = peg$parsespaceNL();
+        while (s5 !== peg$FAILED) {
+          s4.push(s5);
+          s5 = peg$parsespaceNL();
+        }
+        if (s4 !== peg$FAILED) {
+          if (input.substr(peg$currPos, 2) === peg$c234) {
+            s5 = peg$c234;
+            peg$currPos += 2;
+          } else {
+            s5 = peg$FAILED;
+            if (peg$silentFails === 0) { peg$fail(peg$c235); }
+          }
+          if (s5 === peg$FAILED) {
+            if (input.substr(peg$currPos, 2) === peg$c151) {
+              s5 = peg$c151;
+              peg$currPos += 2;
+            } else {
+              s5 = peg$FAILED;
+              if (peg$silentFails === 0) { peg$fail(peg$c152); }
+            }
+          }
+          if (s5 !== peg$FAILED) {
+            s6 = peg$currPos;
+            peg$silentFails++;
+            if (input.charCodeAt(peg$currPos) === 61) {
+              s7 = peg$c72;
+              peg$currPos++;
+            } else {
+              s7 = peg$FAILED;
+              if (peg$silentFails === 0) { peg$fail(peg$c73); }
+            }
+            peg$silentFails--;
+            if (s7 === peg$FAILED) {
+              s6 = void 0;
+            } else {
+              peg$currPos = s6;
+              s6 = peg$FAILED;
+            }
+            if (s6 !== peg$FAILED) {
+              s7 = [];
+              s8 = peg$parsespaceNL();
+              while (s8 !== peg$FAILED) {
+                s7.push(s8);
+                s8 = peg$parsespaceNL();
+              }
+              if (s7 !== peg$FAILED) {
+                s8 = peg$parseaAddSubtract();
+                if (s8 !== peg$FAILED) {
+                  peg$savedPos = s3;
+                  s4 = peg$c215(s1, s5, s8);
+                  s3 = s4;
+                } else {
+                  peg$currPos = s3;
+                  s3 = peg$FAILED;
+                }
+              } else {
+                peg$currPos = s3;
+                s3 = peg$FAILED;
+              }
+            } else {
+              peg$currPos = s3;
+              s3 = peg$FAILED;
+            }
+          } else {
+            peg$currPos = s3;
+            s3 = peg$FAILED;
+          }
+        } else {
+          peg$currPos = s3;
+          s3 = peg$FAILED;
+        }
+        while (s3 !== peg$FAILED) {
+          s2.push(s3);
+          s3 = peg$currPos;
+          s4 = [];
+          s5 = peg$parsespaceNL();
+          while (s5 !== peg$FAILED) {
+            s4.push(s5);
+            s5 = peg$parsespaceNL();
+          }
+          if (s4 !== peg$FAILED) {
+            if (input.substr(peg$currPos, 2) === peg$c234) {
+              s5 = peg$c234;
+              peg$currPos += 2;
+            } else {
+              s5 = peg$FAILED;
+              if (peg$silentFails === 0) { peg$fail(peg$c235); }
+            }
+            if (s5 === peg$FAILED) {
+              if (input.substr(peg$currPos, 2) === peg$c151) {
+                s5 = peg$c151;
+                peg$currPos += 2;
+              } else {
+                s5 = peg$FAILED;
+                if (peg$silentFails === 0) { peg$fail(peg$c152); }
+              }
+            }
+            if (s5 !== peg$FAILED) {
+              s6 = peg$currPos;
+              peg$silentFails++;
+              if (input.charCodeAt(peg$currPos) === 61) {
+                s7 = peg$c72;
+                peg$currPos++;
+              } else {
+                s7 = peg$FAILED;
+                if (peg$silentFails === 0) { peg$fail(peg$c73); }
+              }
+              peg$silentFails--;
+              if (s7 === peg$FAILED) {
+                s6 = void 0;
+              } else {
+                peg$currPos = s6;
+                s6 = peg$FAILED;
+              }
+              if (s6 !== peg$FAILED) {
+                s7 = [];
+                s8 = peg$parsespaceNL();
+                while (s8 !== peg$FAILED) {
+                  s7.push(s8);
+                  s8 = peg$parsespaceNL();
+                }
+                if (s7 !== peg$FAILED) {
+                  s8 = peg$parseaAddSubtract();
+                  if (s8 !== peg$FAILED) {
+                    peg$savedPos = s3;
+                    s4 = peg$c215(s1, s5, s8);
+                    s3 = s4;
+                  } else {
+                    peg$currPos = s3;
+                    s3 = peg$FAILED;
+                  }
+                } else {
+                  peg$currPos = s3;
+                  s3 = peg$FAILED;
+                }
+              } else {
+                peg$currPos = s3;
+                s3 = peg$FAILED;
+              }
+            } else {
+              peg$currPos = s3;
+              s3 = peg$FAILED;
+            }
+          } else {
+            peg$currPos = s3;
+            s3 = peg$FAILED;
+          }
+        }
+        if (s2 !== peg$FAILED) {
+          peg$savedPos = s0;
+          s1 = peg$c220(s1, s2);
+          s0 = s1;
+        } else {
+          peg$currPos = s0;
+          s0 = peg$FAILED;
+        }
+      } else {
+        peg$currPos = s0;
+        s0 = peg$FAILED;
+      }
+
+      return s0;
+    }
+
+    function peg$parseaAddSubtract() {
+      var s0, s1, s2, s3, s4, s5, s6, s7, s8;
+
+      s0 = peg$currPos;
+      s1 = peg$parseaMultDivModulo();
+      if (s1 !== peg$FAILED) {
+        s2 = [];
+        s3 = peg$currPos;
+        s4 = [];
+        s5 = peg$parsespaceNL();
+        while (s5 !== peg$FAILED) {
+          s4.push(s5);
+          s5 = peg$parsespaceNL();
+        }
+        if (s4 !== peg$FAILED) {
+          if (input.charCodeAt(peg$currPos) === 43) {
+            s5 = peg$c236;
+            peg$currPos++;
+          } else {
+            s5 = peg$FAILED;
+            if (peg$silentFails === 0) { peg$fail(peg$c237); }
+          }
+          if (s5 === peg$FAILED) {
+            if (input.charCodeAt(peg$currPos) === 45) {
+              s5 = peg$c59;
+              peg$currPos++;
+            } else {
+              s5 = peg$FAILED;
+              if (peg$silentFails === 0) { peg$fail(peg$c60); }
+            }
+          }
+          if (s5 !== peg$FAILED) {
+            s6 = peg$currPos;
+            peg$silentFails++;
+            if (input.charCodeAt(peg$currPos) === 61) {
+              s7 = peg$c72;
+              peg$currPos++;
+            } else {
+              s7 = peg$FAILED;
+              if (peg$silentFails === 0) { peg$fail(peg$c73); }
+            }
+            peg$silentFails--;
+            if (s7 === peg$FAILED) {
+              s6 = void 0;
+            } else {
+              peg$currPos = s6;
+              s6 = peg$FAILED;
+            }
+            if (s6 !== peg$FAILED) {
+              s7 = [];
+              s8 = peg$parsespaceNL();
+              while (s8 !== peg$FAILED) {
+                s7.push(s8);
+                s8 = peg$parsespaceNL();
+              }
+              if (s7 !== peg$FAILED) {
+                s8 = peg$parseaMultDivModulo();
+                if (s8 !== peg$FAILED) {
+                  peg$savedPos = s3;
+                  s4 = peg$c215(s1, s5, s8);
+                  s3 = s4;
+                } else {
+                  peg$currPos = s3;
+                  s3 = peg$FAILED;
+                }
+              } else {
+                peg$currPos = s3;
+                s3 = peg$FAILED;
+              }
+            } else {
+              peg$currPos = s3;
+              s3 = peg$FAILED;
+            }
+          } else {
+            peg$currPos = s3;
+            s3 = peg$FAILED;
+          }
+        } else {
+          peg$currPos = s3;
+          s3 = peg$FAILED;
+        }
+        while (s3 !== peg$FAILED) {
+          s2.push(s3);
+          s3 = peg$currPos;
+          s4 = [];
+          s5 = peg$parsespaceNL();
+          while (s5 !== peg$FAILED) {
+            s4.push(s5);
+            s5 = peg$parsespaceNL();
+          }
+          if (s4 !== peg$FAILED) {
+            if (input.charCodeAt(peg$currPos) === 43) {
+              s5 = peg$c236;
+              peg$currPos++;
+            } else {
+              s5 = peg$FAILED;
+              if (peg$silentFails === 0) { peg$fail(peg$c237); }
+            }
+            if (s5 === peg$FAILED) {
+              if (input.charCodeAt(peg$currPos) === 45) {
+                s5 = peg$c59;
+                peg$currPos++;
+              } else {
+                s5 = peg$FAILED;
+                if (peg$silentFails === 0) { peg$fail(peg$c60); }
+              }
+            }
+            if (s5 !== peg$FAILED) {
+              s6 = peg$currPos;
+              peg$silentFails++;
+              if (input.charCodeAt(peg$currPos) === 61) {
+                s7 = peg$c72;
+                peg$currPos++;
+              } else {
+                s7 = peg$FAILED;
+                if (peg$silentFails === 0) { peg$fail(peg$c73); }
+              }
+              peg$silentFails--;
+              if (s7 === peg$FAILED) {
+                s6 = void 0;
+              } else {
+                peg$currPos = s6;
+                s6 = peg$FAILED;
+              }
+              if (s6 !== peg$FAILED) {
+                s7 = [];
+                s8 = peg$parsespaceNL();
+                while (s8 !== peg$FAILED) {
+                  s7.push(s8);
+                  s8 = peg$parsespaceNL();
+                }
+                if (s7 !== peg$FAILED) {
+                  s8 = peg$parseaMultDivModulo();
+                  if (s8 !== peg$FAILED) {
+                    peg$savedPos = s3;
+                    s4 = peg$c215(s1, s5, s8);
+                    s3 = s4;
+                  } else {
+                    peg$currPos = s3;
+                    s3 = peg$FAILED;
+                  }
+                } else {
+                  peg$currPos = s3;
+                  s3 = peg$FAILED;
+                }
+              } else {
+                peg$currPos = s3;
+                s3 = peg$FAILED;
+              }
+            } else {
+              peg$currPos = s3;
+              s3 = peg$FAILED;
+            }
+          } else {
+            peg$currPos = s3;
+            s3 = peg$FAILED;
+          }
+        }
+        if (s2 !== peg$FAILED) {
+          peg$savedPos = s0;
+          s1 = peg$c220(s1, s2);
+          s0 = s1;
+        } else {
+          peg$currPos = s0;
+          s0 = peg$FAILED;
+        }
+      } else {
+        peg$currPos = s0;
+        s0 = peg$FAILED;
+      }
+
+      return s0;
+    }
+
+    function peg$parseaMultDivModulo() {
+      var s0, s1, s2, s3, s4, s5, s6, s7, s8;
+
+      s0 = peg$currPos;
+      s1 = peg$parseaExponent();
+      if (s1 !== peg$FAILED) {
+        s2 = [];
+        s3 = peg$currPos;
+        s4 = [];
+        s5 = peg$parsespaceNL();
+        while (s5 !== peg$FAILED) {
+          s4.push(s5);
+          s5 = peg$parsespaceNL();
+        }
+        if (s4 !== peg$FAILED) {
+          s5 = peg$currPos;
+          if (input.charCodeAt(peg$currPos) === 42) {
+            s6 = peg$c94;
+            peg$currPos++;
+          } else {
+            s6 = peg$FAILED;
+            if (peg$silentFails === 0) { peg$fail(peg$c95); }
+          }
+          if (s6 !== peg$FAILED) {
+            s7 = peg$currPos;
+            peg$silentFails++;
+            if (input.charCodeAt(peg$currPos) === 42) {
+              s8 = peg$c94;
+              peg$currPos++;
+            } else {
+              s8 = peg$FAILED;
+              if (peg$silentFails === 0) { peg$fail(peg$c95); }
+            }
+            peg$silentFails--;
+            if (s8 === peg$FAILED) {
+              s7 = void 0;
+            } else {
+              peg$currPos = s7;
+              s7 = peg$FAILED;
+            }
+            if (s7 !== peg$FAILED) {
+              peg$savedPos = s5;
+              s6 = peg$c233(s1, s6);
+              s5 = s6;
+            } else {
+              peg$currPos = s5;
+              s5 = peg$FAILED;
+            }
+          } else {
+            peg$currPos = s5;
+            s5 = peg$FAILED;
+          }
+          if (s5 === peg$FAILED) {
+            if (input.charCodeAt(peg$currPos) === 47) {
+              s5 = peg$c238;
+              peg$currPos++;
+            } else {
+              s5 = peg$FAILED;
+              if (peg$silentFails === 0) { peg$fail(peg$c239); }
+            }
+            if (s5 === peg$FAILED) {
+              if (input.charCodeAt(peg$currPos) === 37) {
+                s5 = peg$c240;
+                peg$currPos++;
+              } else {
+                s5 = peg$FAILED;
+                if (peg$silentFails === 0) { peg$fail(peg$c241); }
+              }
+            }
+          }
+          if (s5 !== peg$FAILED) {
+            s6 = peg$currPos;
+            peg$silentFails++;
+            if (input.charCodeAt(peg$currPos) === 61) {
+              s7 = peg$c72;
+              peg$currPos++;
+            } else {
+              s7 = peg$FAILED;
+              if (peg$silentFails === 0) { peg$fail(peg$c73); }
+            }
+            peg$silentFails--;
+            if (s7 === peg$FAILED) {
+              s6 = void 0;
+            } else {
+              peg$currPos = s6;
+              s6 = peg$FAILED;
+            }
+            if (s6 !== peg$FAILED) {
+              s7 = [];
+              s8 = peg$parsespaceNL();
+              while (s8 !== peg$FAILED) {
+                s7.push(s8);
+                s8 = peg$parsespaceNL();
+              }
+              if (s7 !== peg$FAILED) {
+                s8 = peg$parseaExponent();
+                if (s8 !== peg$FAILED) {
+                  peg$savedPos = s3;
+                  s4 = peg$c215(s1, s5, s8);
+                  s3 = s4;
+                } else {
+                  peg$currPos = s3;
+                  s3 = peg$FAILED;
+                }
+              } else {
+                peg$currPos = s3;
+                s3 = peg$FAILED;
+              }
+            } else {
+              peg$currPos = s3;
+              s3 = peg$FAILED;
+            }
+          } else {
+            peg$currPos = s3;
+            s3 = peg$FAILED;
+          }
+        } else {
+          peg$currPos = s3;
+          s3 = peg$FAILED;
+        }
+        while (s3 !== peg$FAILED) {
+          s2.push(s3);
+          s3 = peg$currPos;
+          s4 = [];
+          s5 = peg$parsespaceNL();
+          while (s5 !== peg$FAILED) {
+            s4.push(s5);
+            s5 = peg$parsespaceNL();
+          }
+          if (s4 !== peg$FAILED) {
+            s5 = peg$currPos;
+            if (input.charCodeAt(peg$currPos) === 42) {
+              s6 = peg$c94;
+              peg$currPos++;
+            } else {
+              s6 = peg$FAILED;
+              if (peg$silentFails === 0) { peg$fail(peg$c95); }
+            }
+            if (s6 !== peg$FAILED) {
+              s7 = peg$currPos;
+              peg$silentFails++;
+              if (input.charCodeAt(peg$currPos) === 42) {
+                s8 = peg$c94;
+                peg$currPos++;
+              } else {
+                s8 = peg$FAILED;
+                if (peg$silentFails === 0) { peg$fail(peg$c95); }
+              }
+              peg$silentFails--;
+              if (s8 === peg$FAILED) {
+                s7 = void 0;
+              } else {
+                peg$currPos = s7;
+                s7 = peg$FAILED;
+              }
+              if (s7 !== peg$FAILED) {
+                peg$savedPos = s5;
+                s6 = peg$c233(s1, s6);
+                s5 = s6;
+              } else {
+                peg$currPos = s5;
+                s5 = peg$FAILED;
+              }
+            } else {
+              peg$currPos = s5;
+              s5 = peg$FAILED;
+            }
+            if (s5 === peg$FAILED) {
+              if (input.charCodeAt(peg$currPos) === 47) {
+                s5 = peg$c238;
+                peg$currPos++;
+              } else {
+                s5 = peg$FAILED;
+                if (peg$silentFails === 0) { peg$fail(peg$c239); }
+              }
+              if (s5 === peg$FAILED) {
+                if (input.charCodeAt(peg$currPos) === 37) {
+                  s5 = peg$c240;
+                  peg$currPos++;
+                } else {
+                  s5 = peg$FAILED;
+                  if (peg$silentFails === 0) { peg$fail(peg$c241); }
+                }
+              }
+            }
+            if (s5 !== peg$FAILED) {
+              s6 = peg$currPos;
+              peg$silentFails++;
+              if (input.charCodeAt(peg$currPos) === 61) {
+                s7 = peg$c72;
+                peg$currPos++;
+              } else {
+                s7 = peg$FAILED;
+                if (peg$silentFails === 0) { peg$fail(peg$c73); }
+              }
+              peg$silentFails--;
+              if (s7 === peg$FAILED) {
+                s6 = void 0;
+              } else {
+                peg$currPos = s6;
+                s6 = peg$FAILED;
+              }
+              if (s6 !== peg$FAILED) {
+                s7 = [];
+                s8 = peg$parsespaceNL();
+                while (s8 !== peg$FAILED) {
+                  s7.push(s8);
+                  s8 = peg$parsespaceNL();
+                }
+                if (s7 !== peg$FAILED) {
+                  s8 = peg$parseaExponent();
+                  if (s8 !== peg$FAILED) {
+                    peg$savedPos = s3;
+                    s4 = peg$c215(s1, s5, s8);
+                    s3 = s4;
+                  } else {
+                    peg$currPos = s3;
+                    s3 = peg$FAILED;
+                  }
+                } else {
+                  peg$currPos = s3;
+                  s3 = peg$FAILED;
+                }
+              } else {
+                peg$currPos = s3;
+                s3 = peg$FAILED;
+              }
+            } else {
+              peg$currPos = s3;
+              s3 = peg$FAILED;
+            }
+          } else {
+            peg$currPos = s3;
+            s3 = peg$FAILED;
+          }
+        }
+        if (s2 !== peg$FAILED) {
+          peg$savedPos = s0;
+          s1 = peg$c220(s1, s2);
+          s0 = s1;
+        } else {
+          peg$currPos = s0;
+          s0 = peg$FAILED;
+        }
+      } else {
+        peg$currPos = s0;
+        s0 = peg$FAILED;
+      }
+
+      return s0;
+    }
+
+    function peg$parseaExponent() {
+      var s0, s1, s2, s3, s4, s5, s6, s7;
+
+      s0 = peg$currPos;
+      s1 = peg$parseaNegation();
+      if (s1 !== peg$FAILED) {
+        s2 = [];
+        s3 = peg$currPos;
+        s4 = [];
+        s5 = peg$parsespaceNL();
+        while (s5 !== peg$FAILED) {
+          s4.push(s5);
+          s5 = peg$parsespaceNL();
+        }
+        if (s4 !== peg$FAILED) {
+          if (input.substr(peg$currPos, 2) === peg$c242) {
+            s5 = peg$c242;
+            peg$currPos += 2;
+          } else {
+            s5 = peg$FAILED;
+            if (peg$silentFails === 0) { peg$fail(peg$c243); }
+          }
+          if (s5 !== peg$FAILED) {
+            s6 = [];
+            s7 = peg$parsespaceNL();
+            while (s7 !== peg$FAILED) {
+              s6.push(s7);
+              s7 = peg$parsespaceNL();
+            }
+            if (s6 !== peg$FAILED) {
+              s7 = peg$parseaNegation();
+              if (s7 !== peg$FAILED) {
+                peg$savedPos = s3;
+                s4 = peg$c215(s1, s5, s7);
+                s3 = s4;
+              } else {
+                peg$currPos = s3;
+                s3 = peg$FAILED;
+              }
+            } else {
+              peg$currPos = s3;
+              s3 = peg$FAILED;
+            }
+          } else {
+            peg$currPos = s3;
+            s3 = peg$FAILED;
+          }
+        } else {
+          peg$currPos = s3;
+          s3 = peg$FAILED;
+        }
+        while (s3 !== peg$FAILED) {
+          s2.push(s3);
+          s3 = peg$currPos;
+          s4 = [];
+          s5 = peg$parsespaceNL();
+          while (s5 !== peg$FAILED) {
+            s4.push(s5);
+            s5 = peg$parsespaceNL();
+          }
+          if (s4 !== peg$FAILED) {
+            if (input.substr(peg$currPos, 2) === peg$c242) {
+              s5 = peg$c242;
+              peg$currPos += 2;
+            } else {
+              s5 = peg$FAILED;
+              if (peg$silentFails === 0) { peg$fail(peg$c243); }
+            }
+            if (s5 !== peg$FAILED) {
+              s6 = [];
+              s7 = peg$parsespaceNL();
+              while (s7 !== peg$FAILED) {
+                s6.push(s7);
+                s7 = peg$parsespaceNL();
+              }
+              if (s6 !== peg$FAILED) {
+                s7 = peg$parseaNegation();
+                if (s7 !== peg$FAILED) {
+                  peg$savedPos = s3;
+                  s4 = peg$c215(s1, s5, s7);
+                  s3 = s4;
+                } else {
+                  peg$currPos = s3;
+                  s3 = peg$FAILED;
+                }
+              } else {
+                peg$currPos = s3;
+                s3 = peg$FAILED;
+              }
+            } else {
+              peg$currPos = s3;
+              s3 = peg$FAILED;
+            }
+          } else {
+            peg$currPos = s3;
+            s3 = peg$FAILED;
+          }
+        }
+        if (s2 !== peg$FAILED) {
+          peg$savedPos = s0;
+          s1 = peg$c220(s1, s2);
+          s0 = s1;
+        } else {
+          peg$currPos = s0;
+          s0 = peg$FAILED;
+        }
+      } else {
+        peg$currPos = s0;
+        s0 = peg$FAILED;
+      }
+
+      return s0;
+    }
+
+    function peg$parseaNegation() {
+      var s0, s1, s2, s3;
+
+      s0 = peg$currPos;
+      if (input.charCodeAt(peg$currPos) === 33) {
+        s1 = peg$c244;
+        peg$currPos++;
+      } else {
+        s1 = peg$FAILED;
+        if (peg$silentFails === 0) { peg$fail(peg$c245); }
+      }
+      if (s1 === peg$FAILED) {
+        if (input.charCodeAt(peg$currPos) === 126) {
+          s1 = peg$c246;
+          peg$currPos++;
+        } else {
+          s1 = peg$FAILED;
+          if (peg$silentFails === 0) { peg$fail(peg$c247); }
+        }
+      }
+      if (s1 !== peg$FAILED) {
+        s2 = [];
+        s3 = peg$parsespaceNL();
+        while (s3 !== peg$FAILED) {
+          s2.push(s3);
+          s3 = peg$parsespaceNL();
+        }
+        if (s2 !== peg$FAILED) {
+          s3 = peg$parseaNegation();
+          if (s3 !== peg$FAILED) {
+            peg$savedPos = s0;
+            s1 = peg$c248(s1, s3);
+            s0 = s1;
+          } else {
+            peg$currPos = s0;
+            s0 = peg$FAILED;
+          }
+        } else {
+          peg$currPos = s0;
+          s0 = peg$FAILED;
+        }
+      } else {
+        peg$currPos = s0;
+        s0 = peg$FAILED;
+      }
+      if (s0 === peg$FAILED) {
+        s0 = peg$currPos;
+        s1 = peg$parseaUnary();
+        if (s1 !== peg$FAILED) {
+          peg$savedPos = s0;
+          s1 = peg$c209(s1);
+        }
+        s0 = s1;
+      }
+
+      return s0;
+    }
+
+    function peg$parseaUnary() {
+      var s0, s1, s2, s3, s4;
+
+      s0 = peg$currPos;
+      s1 = peg$currPos;
+      if (input.charCodeAt(peg$currPos) === 43) {
+        s2 = peg$c236;
+        peg$currPos++;
+      } else {
+        s2 = peg$FAILED;
+        if (peg$silentFails === 0) { peg$fail(peg$c237); }
+      }
+      if (s2 !== peg$FAILED) {
+        s3 = peg$currPos;
+        peg$silentFails++;
+        if (peg$c249.test(input.charAt(peg$currPos))) {
+          s4 = input.charAt(peg$currPos);
+          peg$currPos++;
+        } else {
+          s4 = peg$FAILED;
+          if (peg$silentFails === 0) { peg$fail(peg$c250); }
+        }
+        peg$silentFails--;
+        if (s4 === peg$FAILED) {
+          s3 = void 0;
+        } else {
+          peg$currPos = s3;
+          s3 = peg$FAILED;
+        }
+        if (s3 !== peg$FAILED) {
+          peg$savedPos = s1;
+          s2 = peg$c251(s2);
+          s1 = s2;
+        } else {
+          peg$currPos = s1;
+          s1 = peg$FAILED;
+        }
+      } else {
+        peg$currPos = s1;
+        s1 = peg$FAILED;
+      }
+      if (s1 === peg$FAILED) {
+        s1 = peg$currPos;
+        if (input.charCodeAt(peg$currPos) === 45) {
+          s2 = peg$c59;
+          peg$currPos++;
+        } else {
+          s2 = peg$FAILED;
+          if (peg$silentFails === 0) { peg$fail(peg$c60); }
+        }
+        if (s2 !== peg$FAILED) {
+          s3 = peg$currPos;
+          peg$silentFails++;
+          if (peg$c252.test(input.charAt(peg$currPos))) {
+            s4 = input.charAt(peg$currPos);
+            peg$currPos++;
+          } else {
+            s4 = peg$FAILED;
+            if (peg$silentFails === 0) { peg$fail(peg$c253); }
+          }
+          peg$silentFails--;
+          if (s4 === peg$FAILED) {
+            s3 = void 0;
+          } else {
+            peg$currPos = s3;
+            s3 = peg$FAILED;
+          }
+          if (s3 !== peg$FAILED) {
+            peg$savedPos = s1;
+            s2 = peg$c251(s2);
+            s1 = s2;
+          } else {
+            peg$currPos = s1;
+            s1 = peg$FAILED;
+          }
+        } else {
+          peg$currPos = s1;
+          s1 = peg$FAILED;
+        }
+      }
+      if (s1 !== peg$FAILED) {
+        s2 = [];
+        s3 = peg$parsespaceNL();
+        while (s3 !== peg$FAILED) {
+          s2.push(s3);
+          s3 = peg$parsespaceNL();
+        }
+        if (s2 !== peg$FAILED) {
+          s3 = peg$parseaUnary();
+          if (s3 !== peg$FAILED) {
+            peg$savedPos = s0;
+            s1 = peg$c248(s1, s3);
+            s0 = s1;
+          } else {
+            peg$currPos = s0;
+            s0 = peg$FAILED;
+          }
+        } else {
+          peg$currPos = s0;
+          s0 = peg$FAILED;
+        }
+      } else {
+        peg$currPos = s0;
+        s0 = peg$FAILED;
+      }
+      if (s0 === peg$FAILED) {
+        s0 = peg$currPos;
+        s1 = peg$parseaPreIncDec();
+        if (s1 !== peg$FAILED) {
+          peg$savedPos = s0;
+          s1 = peg$c209(s1);
+        }
+        s0 = s1;
+      }
+
+      return s0;
+    }
+
+    function peg$parseaPreIncDec() {
+      var s0, s1, s2, s3;
+
+      s0 = peg$currPos;
+      if (input.substr(peg$currPos, 2) === peg$c254) {
+        s1 = peg$c254;
+        peg$currPos += 2;
+      } else {
+        s1 = peg$FAILED;
+        if (peg$silentFails === 0) { peg$fail(peg$c255); }
+      }
+      if (s1 === peg$FAILED) {
+        if (input.substr(peg$currPos, 2) === peg$c256) {
+          s1 = peg$c256;
+          peg$currPos += 2;
+        } else {
+          s1 = peg$FAILED;
+          if (peg$silentFails === 0) { peg$fail(peg$c257); }
+        }
+      }
+      if (s1 !== peg$FAILED) {
+        s2 = [];
+        s3 = peg$parsespaceNL();
+        while (s3 !== peg$FAILED) {
+          s2.push(s3);
+          s3 = peg$parsespaceNL();
+        }
+        if (s2 !== peg$FAILED) {
+          s3 = peg$parseaPreIncDec();
+          if (s3 !== peg$FAILED) {
+            peg$savedPos = s0;
+            s1 = peg$c258(s1, s3);
+            s0 = s1;
+          } else {
+            peg$currPos = s0;
+            s0 = peg$FAILED;
+          }
+        } else {
+          peg$currPos = s0;
+          s0 = peg$FAILED;
+        }
+      } else {
+        peg$currPos = s0;
+        s0 = peg$FAILED;
+      }
+      if (s0 === peg$FAILED) {
+        s0 = peg$currPos;
+        s1 = peg$parseaPostIncDec();
+        if (s1 !== peg$FAILED) {
+          peg$savedPos = s0;
+          s1 = peg$c209(s1);
+        }
+        s0 = s1;
+      }
+
+      return s0;
+    }
+
+    function peg$parseaPostIncDec() {
+      var s0, s1, s2, s3, s4, s5;
+
+      s0 = peg$currPos;
+      s1 = peg$parseaMemberExpr();
+      if (s1 !== peg$FAILED) {
+        s2 = [];
+        s3 = peg$currPos;
+        s4 = [];
+        s5 = peg$parsespaceNL();
+        while (s5 !== peg$FAILED) {
+          s4.push(s5);
+          s5 = peg$parsespaceNL();
+        }
+        if (s4 !== peg$FAILED) {
+          if (input.substr(peg$currPos, 2) === peg$c254) {
+            s5 = peg$c254;
+            peg$currPos += 2;
+          } else {
+            s5 = peg$FAILED;
+            if (peg$silentFails === 0) { peg$fail(peg$c255); }
+          }
+          if (s5 === peg$FAILED) {
+            if (input.substr(peg$currPos, 2) === peg$c256) {
+              s5 = peg$c256;
+              peg$currPos += 2;
+            } else {
+              s5 = peg$FAILED;
+              if (peg$silentFails === 0) { peg$fail(peg$c257); }
+            }
+          }
+          if (s5 !== peg$FAILED) {
+            peg$savedPos = s3;
+            s4 = peg$c259(s1, s5);
+            s3 = s4;
+          } else {
+            peg$currPos = s3;
+            s3 = peg$FAILED;
+          }
+        } else {
+          peg$currPos = s3;
+          s3 = peg$FAILED;
+        }
+        if (s3 !== peg$FAILED) {
+          while (s3 !== peg$FAILED) {
+            s2.push(s3);
+            s3 = peg$currPos;
+            s4 = [];
+            s5 = peg$parsespaceNL();
+            while (s5 !== peg$FAILED) {
+              s4.push(s5);
+              s5 = peg$parsespaceNL();
+            }
+            if (s4 !== peg$FAILED) {
+              if (input.substr(peg$currPos, 2) === peg$c254) {
+                s5 = peg$c254;
+                peg$currPos += 2;
+              } else {
+                s5 = peg$FAILED;
+                if (peg$silentFails === 0) { peg$fail(peg$c255); }
+              }
+              if (s5 === peg$FAILED) {
+                if (input.substr(peg$currPos, 2) === peg$c256) {
+                  s5 = peg$c256;
+                  peg$currPos += 2;
+                } else {
+                  s5 = peg$FAILED;
+                  if (peg$silentFails === 0) { peg$fail(peg$c257); }
+                }
+              }
+              if (s5 !== peg$FAILED) {
+                peg$savedPos = s3;
+                s4 = peg$c259(s1, s5);
+                s3 = s4;
+              } else {
+                peg$currPos = s3;
+                s3 = peg$FAILED;
+              }
+            } else {
+              peg$currPos = s3;
+              s3 = peg$FAILED;
+            }
+          }
+        } else {
+          s2 = peg$FAILED;
+        }
+        if (s2 !== peg$FAILED) {
+          peg$savedPos = s0;
+          s1 = peg$c260(s1, s2);
+          s0 = s1;
+        } else {
+          peg$currPos = s0;
+          s0 = peg$FAILED;
+        }
+      } else {
+        peg$currPos = s0;
+        s0 = peg$FAILED;
+      }
+      if (s0 === peg$FAILED) {
+        s0 = peg$currPos;
+        s1 = peg$parseaMemberExpr();
+        if (s1 !== peg$FAILED) {
+          peg$savedPos = s0;
+          s1 = peg$c209(s1);
+        }
+        s0 = s1;
+      }
+
+      return s0;
+    }
+
+    function peg$parseaMemberExpr() {
+      var s0, s1, s2, s3, s4, s5, s6, s7;
+
+      s0 = peg$currPos;
+      s1 = peg$parseaParenExpr();
+      if (s1 !== peg$FAILED) {
+        s2 = [];
+        s3 = peg$currPos;
+        s4 = [];
+        s5 = peg$parsespaceNL();
+        while (s5 !== peg$FAILED) {
+          s4.push(s5);
+          s5 = peg$parsespaceNL();
+        }
+        if (s4 !== peg$FAILED) {
+          if (input.charCodeAt(peg$currPos) === 91) {
+            s5 = peg$c79;
+            peg$currPos++;
+          } else {
+            s5 = peg$FAILED;
+            if (peg$silentFails === 0) { peg$fail(peg$c80); }
+          }
+          if (s5 !== peg$FAILED) {
+            s6 = peg$parsearithmetic();
+            if (s6 !== peg$FAILED) {
+              if (input.charCodeAt(peg$currPos) === 93) {
+                s7 = peg$c99;
+                peg$currPos++;
+              } else {
+                s7 = peg$FAILED;
+                if (peg$silentFails === 0) { peg$fail(peg$c100); }
+              }
+              if (s7 !== peg$FAILED) {
+                peg$savedPos = s3;
+                s4 = peg$c261(s1, s6);
+                s3 = s4;
+              } else {
+                peg$currPos = s3;
+                s3 = peg$FAILED;
+              }
+            } else {
+              peg$currPos = s3;
+              s3 = peg$FAILED;
+            }
+          } else {
+            peg$currPos = s3;
+            s3 = peg$FAILED;
+          }
+        } else {
+          peg$currPos = s3;
+          s3 = peg$FAILED;
+        }
+        while (s3 !== peg$FAILED) {
+          s2.push(s3);
+          s3 = peg$currPos;
+          s4 = [];
+          s5 = peg$parsespaceNL();
+          while (s5 !== peg$FAILED) {
+            s4.push(s5);
+            s5 = peg$parsespaceNL();
+          }
+          if (s4 !== peg$FAILED) {
+            if (input.charCodeAt(peg$currPos) === 91) {
+              s5 = peg$c79;
+              peg$currPos++;
+            } else {
+              s5 = peg$FAILED;
+              if (peg$silentFails === 0) { peg$fail(peg$c80); }
+            }
+            if (s5 !== peg$FAILED) {
+              s6 = peg$parsearithmetic();
+              if (s6 !== peg$FAILED) {
+                if (input.charCodeAt(peg$currPos) === 93) {
+                  s7 = peg$c99;
+                  peg$currPos++;
+                } else {
+                  s7 = peg$FAILED;
+                  if (peg$silentFails === 0) { peg$fail(peg$c100); }
+                }
+                if (s7 !== peg$FAILED) {
+                  peg$savedPos = s3;
+                  s4 = peg$c261(s1, s6);
+                  s3 = s4;
+                } else {
+                  peg$currPos = s3;
+                  s3 = peg$FAILED;
+                }
+              } else {
+                peg$currPos = s3;
+                s3 = peg$FAILED;
+              }
+            } else {
+              peg$currPos = s3;
+              s3 = peg$FAILED;
+            }
+          } else {
+            peg$currPos = s3;
+            s3 = peg$FAILED;
+          }
+        }
+        if (s2 !== peg$FAILED) {
+          peg$savedPos = s0;
+          s1 = peg$c262(s1, s2);
+          s0 = s1;
+        } else {
+          peg$currPos = s0;
+          s0 = peg$FAILED;
+        }
+      } else {
+        peg$currPos = s0;
+        s0 = peg$FAILED;
+      }
+
+      return s0;
+    }
+
+    function peg$parseaParenExpr() {
+      var s0, s1, s2, s3, s4, s5;
+
+      s0 = peg$currPos;
+      if (input.charCodeAt(peg$currPos) === 40) {
+        s1 = peg$c15;
+        peg$currPos++;
+      } else {
+        s1 = peg$FAILED;
+        if (peg$silentFails === 0) { peg$fail(peg$c16); }
+      }
+      if (s1 !== peg$FAILED) {
+        s2 = [];
+        s3 = peg$parsespaceNL();
+        while (s3 !== peg$FAILED) {
+          s2.push(s3);
+          s3 = peg$parsespaceNL();
+        }
+        if (s2 !== peg$FAILED) {
+          s3 = peg$parsearithmetic();
+          if (s3 !== peg$FAILED) {
+            s4 = [];
+            s5 = peg$parsespaceNL();
+            while (s5 !== peg$FAILED) {
+              s4.push(s5);
+              s5 = peg$parsespaceNL();
+            }
+            if (s4 !== peg$FAILED) {
+              if (input.charCodeAt(peg$currPos) === 41) {
+                s5 = peg$c17;
+                peg$currPos++;
+              } else {
+                s5 = peg$FAILED;
+                if (peg$silentFails === 0) { peg$fail(peg$c18); }
+              }
+              if (s5 !== peg$FAILED) {
+                peg$savedPos = s0;
+                s1 = peg$c263(s3);
+                s0 = s1;
+              } else {
+                peg$currPos = s0;
+                s0 = peg$FAILED;
+              }
+            } else {
+              peg$currPos = s0;
+              s0 = peg$FAILED;
+            }
+          } else {
+            peg$currPos = s0;
+            s0 = peg$FAILED;
+          }
+        } else {
+          peg$currPos = s0;
+          s0 = peg$FAILED;
+        }
+      } else {
+        peg$currPos = s0;
+        s0 = peg$FAILED;
+      }
+      if (s0 === peg$FAILED) {
+        s0 = peg$currPos;
+        s1 = peg$parseaLiteral();
+        if (s1 !== peg$FAILED) {
+          peg$savedPos = s0;
+          s1 = peg$c209(s1);
+        }
+        s0 = s1;
+      }
+
+      return s0;
+    }
+
+    function peg$parseaBareword() {
+      var s0, s1, s2, s3;
+
+      peg$silentFails++;
+      s0 = peg$currPos;
+      s1 = peg$currPos;
+      peg$silentFails++;
+      if (input.charCodeAt(peg$currPos) === 35) {
+        s2 = peg$c85;
+        peg$currPos++;
+      } else {
+        s2 = peg$FAILED;
+        if (peg$silentFails === 0) { peg$fail(peg$c86); }
+      }
+      peg$silentFails--;
+      if (s2 === peg$FAILED) {
+        s1 = void 0;
+      } else {
+        peg$currPos = s1;
+        s1 = peg$FAILED;
+      }
+      if (s1 !== peg$FAILED) {
+        s2 = [];
+        s3 = peg$parseaBarewordChar();
+        if (s3 !== peg$FAILED) {
+          while (s3 !== peg$FAILED) {
+            s2.push(s3);
+            s3 = peg$parseaBarewordChar();
+          }
+        } else {
+          s2 = peg$FAILED;
+        }
+        if (s2 !== peg$FAILED) {
+          peg$savedPos = s0;
+          s1 = peg$c265(s2);
+          s0 = s1;
+        } else {
+          peg$currPos = s0;
+          s0 = peg$FAILED;
+        }
+      } else {
+        peg$currPos = s0;
+        s0 = peg$FAILED;
+      }
+      peg$silentFails--;
+      if (s0 === peg$FAILED) {
+        s1 = peg$FAILED;
+        if (peg$silentFails === 0) { peg$fail(peg$c264); }
+      }
+
+      return s0;
+    }
+
+    function peg$parseaBarewordChar() {
+      var s0, s1, s2;
+
+      s0 = peg$currPos;
+      if (input.charCodeAt(peg$currPos) === 92) {
+        s1 = peg$c88;
+        peg$currPos++;
+      } else {
+        s1 = peg$FAILED;
+        if (peg$silentFails === 0) { peg$fail(peg$c89); }
+      }
+      if (s1 !== peg$FAILED) {
+        s2 = peg$parseaBarewordMeta();
+        if (s2 !== peg$FAILED) {
+          peg$savedPos = s0;
+          s1 = peg$c90(s2);
+          s0 = s1;
+        } else {
+          peg$currPos = s0;
+          s0 = peg$FAILED;
+        }
+      } else {
+        peg$currPos = s0;
+        s0 = peg$FAILED;
+      }
+      if (s0 === peg$FAILED) {
+        s0 = peg$currPos;
+        s1 = peg$currPos;
+        peg$silentFails++;
+        s2 = peg$parseaBarewordMeta();
+        peg$silentFails--;
+        if (s2 === peg$FAILED) {
+          s1 = void 0;
+        } else {
+          peg$currPos = s1;
+          s1 = peg$FAILED;
+        }
+        if (s1 !== peg$FAILED) {
+          if (input.length > peg$currPos) {
+            s2 = input.charAt(peg$currPos);
+            peg$currPos++;
+          } else {
+            s2 = peg$FAILED;
+            if (peg$silentFails === 0) { peg$fail(peg$c91); }
+          }
+          if (s2 !== peg$FAILED) {
+            peg$savedPos = s0;
+            s1 = peg$c90(s2);
+            s0 = s1;
+          } else {
+            peg$currPos = s0;
+            s0 = peg$FAILED;
+          }
+        } else {
+          peg$currPos = s0;
+          s0 = peg$FAILED;
+        }
+      }
+
+      return s0;
+    }
+
+    function peg$parseaBarewordMeta() {
+      var s0;
+
+      if (peg$c266.test(input.charAt(peg$currPos))) {
+        s0 = input.charAt(peg$currPos);
+        peg$currPos++;
+      } else {
+        s0 = peg$FAILED;
+        if (peg$silentFails === 0) { peg$fail(peg$c267); }
+      }
+
+      return s0;
+    }
+
+    function peg$parseaConcatenation() {
+      var s0, s1, s2;
+
+      peg$silentFails++;
+      s0 = peg$currPos;
+      s1 = [];
+      s2 = peg$parseaBareword();
+      if (s2 === peg$FAILED) {
+        s2 = peg$parseenvironmentVariable();
+        if (s2 === peg$FAILED) {
+          s2 = peg$parsevariableSubstitution();
+          if (s2 === peg$FAILED) {
+            s2 = peg$parsearithmeticSubstitution();
+            if (s2 === peg$FAILED) {
+              s2 = peg$parsecommandSubstitution();
+              if (s2 === peg$FAILED) {
+                s2 = peg$parsesingleQuote();
+                if (s2 === peg$FAILED) {
+                  s2 = peg$parsedoubleQuote();
+                }
+              }
+            }
+          }
+        }
+      }
+      if (s2 !== peg$FAILED) {
+        while (s2 !== peg$FAILED) {
+          s1.push(s2);
+          s2 = peg$parseaBareword();
+          if (s2 === peg$FAILED) {
+            s2 = peg$parseenvironmentVariable();
+            if (s2 === peg$FAILED) {
+              s2 = peg$parsevariableSubstitution();
+              if (s2 === peg$FAILED) {
+                s2 = peg$parsearithmeticSubstitution();
+                if (s2 === peg$FAILED) {
+                  s2 = peg$parsecommandSubstitution();
+                  if (s2 === peg$FAILED) {
+                    s2 = peg$parsesingleQuote();
+                    if (s2 === peg$FAILED) {
+                      s2 = peg$parsedoubleQuote();
+                    }
+                  }
+                }
+              }
+            }
+          }
+        }
+      } else {
+        s1 = peg$FAILED;
+      }
+      if (s1 !== peg$FAILED) {
+        peg$savedPos = s0;
+        s1 = peg$c268(s1);
+      }
+      s0 = s1;
+      peg$silentFails--;
+      if (s0 === peg$FAILED) {
+        s1 = peg$FAILED;
+        if (peg$silentFails === 0) { peg$fail(peg$c82); }
+      }
+
+      return s0;
+    }
+
+    function peg$parseaLiteral() {
+      var s0, s1;
+
+      s0 = peg$currPos;
+      s1 = peg$parseaNumber();
+      if (s1 !== peg$FAILED) {
+        peg$savedPos = s0;
+        s1 = peg$c269(s1);
+      }
+      s0 = s1;
+      if (s0 === peg$FAILED) {
+        s0 = peg$currPos;
+        s1 = peg$parseaConcatenation();
+        if (s1 !== peg$FAILED) {
+          peg$savedPos = s0;
+          s1 = peg$c269(s1);
+        }
+        s0 = s1;
+      }
+
+      return s0;
+    }
+
+    function peg$parseaNumber() {
+      var s0, s1, s2, s3, s4;
+
+      s0 = peg$currPos;
+      if (input.charCodeAt(peg$currPos) === 48) {
+        s1 = peg$c270;
+        peg$currPos++;
+      } else {
+        s1 = peg$FAILED;
+        if (peg$silentFails === 0) { peg$fail(peg$c271); }
+      }
+      if (s1 !== peg$FAILED) {
+        if (peg$c272.test(input.charAt(peg$currPos))) {
+          s2 = input.charAt(peg$currPos);
+          peg$currPos++;
+        } else {
+          s2 = peg$FAILED;
+          if (peg$silentFails === 0) { peg$fail(peg$c273); }
+        }
+        if (s2 !== peg$FAILED) {
+          s3 = [];
+          if (peg$c274.test(input.charAt(peg$currPos))) {
+            s4 = input.charAt(peg$currPos);
+            peg$currPos++;
+          } else {
+            s4 = peg$FAILED;
+            if (peg$silentFails === 0) { peg$fail(peg$c275); }
+          }
+          if (s4 !== peg$FAILED) {
+            while (s4 !== peg$FAILED) {
+              s3.push(s4);
+              if (peg$c274.test(input.charAt(peg$currPos))) {
+                s4 = input.charAt(peg$currPos);
+                peg$currPos++;
+              } else {
+                s4 = peg$FAILED;
+                if (peg$silentFails === 0) { peg$fail(peg$c275); }
+              }
+            }
+          } else {
+            s3 = peg$FAILED;
+          }
+          if (s3 !== peg$FAILED) {
+            peg$savedPos = s0;
+            s1 = peg$c276(s3);
+            s0 = s1;
+          } else {
+            peg$currPos = s0;
+            s0 = peg$FAILED;
+          }
+        } else {
+          peg$currPos = s0;
+          s0 = peg$FAILED;
+        }
+      } else {
+        peg$currPos = s0;
+        s0 = peg$FAILED;
+      }
+      if (s0 === peg$FAILED) {
+        s0 = peg$currPos;
+        s1 = [];
+        if (peg$c161.test(input.charAt(peg$currPos))) {
+          s2 = input.charAt(peg$currPos);
+          peg$currPos++;
+        } else {
+          s2 = peg$FAILED;
+          if (peg$silentFails === 0) { peg$fail(peg$c162); }
+        }
+        if (s2 !== peg$FAILED) {
+          while (s2 !== peg$FAILED) {
+            s1.push(s2);
+            if (peg$c161.test(input.charAt(peg$currPos))) {
+              s2 = input.charAt(peg$currPos);
+              peg$currPos++;
+            } else {
+              s2 = peg$FAILED;
+              if (peg$silentFails === 0) { peg$fail(peg$c162); }
+            }
+          }
+        } else {
+          s1 = peg$FAILED;
+        }
+        if (s1 !== peg$FAILED) {
+          if (input.charCodeAt(peg$currPos) === 35) {
+            s2 = peg$c85;
+            peg$currPos++;
+          } else {
+            s2 = peg$FAILED;
+            if (peg$silentFails === 0) { peg$fail(peg$c86); }
+          }
+          if (s2 !== peg$FAILED) {
+            s3 = [];
+            if (peg$c277.test(input.charAt(peg$currPos))) {
+              s4 = input.charAt(peg$currPos);
+              peg$currPos++;
+            } else {
+              s4 = peg$FAILED;
+              if (peg$silentFails === 0) { peg$fail(peg$c278); }
+            }
+            if (s4 !== peg$FAILED) {
+              while (s4 !== peg$FAILED) {
+                s3.push(s4);
+                if (peg$c277.test(input.charAt(peg$currPos))) {
+                  s4 = input.charAt(peg$currPos);
+                  peg$currPos++;
+                } else {
+                  s4 = peg$FAILED;
+                  if (peg$silentFails === 0) { peg$fail(peg$c278); }
+                }
+              }
+            } else {
+              s3 = peg$FAILED;
+            }
+            if (s3 !== peg$FAILED) {
+              peg$savedPos = s0;
+              s1 = peg$c279(s1, s3);
+              s0 = s1;
+            } else {
+              peg$currPos = s0;
+              s0 = peg$FAILED;
+            }
+          } else {
+            peg$currPos = s0;
+            s0 = peg$FAILED;
+          }
+        } else {
+          peg$currPos = s0;
+          s0 = peg$FAILED;
+        }
+        if (s0 === peg$FAILED) {
+          s0 = peg$currPos;
+          if (input.charCodeAt(peg$currPos) === 48) {
+            s1 = peg$c270;
+            peg$currPos++;
+          } else {
+            s1 = peg$FAILED;
+            if (peg$silentFails === 0) { peg$fail(peg$c271); }
+          }
+          if (s1 !== peg$FAILED) {
+            s2 = [];
+            if (peg$c280.test(input.charAt(peg$currPos))) {
+              s3 = input.charAt(peg$currPos);
+              peg$currPos++;
+            } else {
+              s3 = peg$FAILED;
+              if (peg$silentFails === 0) { peg$fail(peg$c281); }
+            }
+            if (s3 !== peg$FAILED) {
+              while (s3 !== peg$FAILED) {
+                s2.push(s3);
+                if (peg$c280.test(input.charAt(peg$currPos))) {
+                  s3 = input.charAt(peg$currPos);
+                  peg$currPos++;
+                } else {
+                  s3 = peg$FAILED;
+                  if (peg$silentFails === 0) { peg$fail(peg$c281); }
+                }
+              }
+            } else {
+              s2 = peg$FAILED;
+            }
+            if (s2 !== peg$FAILED) {
+              peg$savedPos = s0;
+              s1 = peg$c282(s2);
+              s0 = s1;
+            } else {
+              peg$currPos = s0;
+              s0 = peg$FAILED;
+            }
+          } else {
+            peg$currPos = s0;
+            s0 = peg$FAILED;
+          }
+          if (s0 === peg$FAILED) {
+            s0 = peg$currPos;
+            s1 = [];
+            if (peg$c161.test(input.charAt(peg$currPos))) {
+              s2 = input.charAt(peg$currPos);
+              peg$currPos++;
+            } else {
+              s2 = peg$FAILED;
+              if (peg$silentFails === 0) { peg$fail(peg$c162); }
+            }
+            if (s2 !== peg$FAILED) {
+              while (s2 !== peg$FAILED) {
+                s1.push(s2);
+                if (peg$c161.test(input.charAt(peg$currPos))) {
+                  s2 = input.charAt(peg$currPos);
+                  peg$currPos++;
+                } else {
+                  s2 = peg$FAILED;
+                  if (peg$silentFails === 0) { peg$fail(peg$c162); }
+                }
+              }
+            } else {
+              s1 = peg$FAILED;
+            }
+            if (s1 !== peg$FAILED) {
+              peg$savedPos = s0;
+              s1 = peg$c283(s1);
+            }
+            s0 = s1;
+          }
+        }
+      }
+
+      return s0;
+    }
+
+    function peg$parsecontinuationStart() {
+      var s0, s1, s2, s3;
+
+      s0 = peg$currPos;
+      s1 = peg$currPos;
+      peg$silentFails++;
+      s2 = peg$parsekeyword();
+      if (s2 === peg$FAILED) {
+        if (input.charCodeAt(peg$currPos) === 34) {
+          s2 = peg$c112;
+          peg$currPos++;
+        } else {
+          s2 = peg$FAILED;
+          if (peg$silentFails === 0) { peg$fail(peg$c113); }
+        }
+        if (s2 === peg$FAILED) {
+          if (input.charCodeAt(peg$currPos) === 39) {
+            s2 = peg$c107;
+            peg$currPos++;
+          } else {
+            s2 = peg$FAILED;
+            if (peg$silentFails === 0) { peg$fail(peg$c108); }
+          }
+          if (s2 === peg$FAILED) {
+            if (input.charCodeAt(peg$currPos) === 96) {
+              s2 = peg$c118;
+              peg$currPos++;
+            } else {
+              s2 = peg$FAILED;
+              if (peg$silentFails === 0) { peg$fail(peg$c119); }
+            }
+            if (s2 === peg$FAILED) {
+              if (input.substr(peg$currPos, 2) === peg$c129) {
+                s2 = peg$c129;
+                peg$currPos += 2;
+              } else {
+                s2 = peg$FAILED;
+                if (peg$silentFails === 0) { peg$fail(peg$c130); }
+              }
+              if (s2 === peg$FAILED) {
+                if (input.substr(peg$currPos, 3) === peg$c132) {
+                  s2 = peg$c132;
+                  peg$currPos += 3;
+                } else {
                   s2 = peg$FAILED;
-                  if (peg$silentFails === 0) { peg$fail(peg$c119); }
+                  if (peg$silentFails === 0) { peg$fail(peg$c133); }
+                }
+                if (s2 === peg$FAILED) {
+                  if (input.substr(peg$currPos, 2) === peg$c124) {
+                    s2 = peg$c124;
+                    peg$currPos += 2;
+                  } else {
+                    s2 = peg$FAILED;
+                    if (peg$silentFails === 0) { peg$fail(peg$c125); }
+                  }
                 }
               }
             }
@@ -3883,7 +7465,7 @@ var parser=(function() {
           peg$currPos++;
         } else {
           s3 = peg$FAILED;
-          if (peg$silentFails === 0) { peg$fail(peg$c85); }
+          if (peg$silentFails === 0) { peg$fail(peg$c91); }
         }
         while (s3 !== peg$FAILED) {
           s2.push(s3);
@@ -3892,7 +7474,7 @@ var parser=(function() {
             peg$currPos++;
           } else {
             s3 = peg$FAILED;
-            if (peg$silentFails === 0) { peg$fail(peg$c85); }
+            if (peg$silentFails === 0) { peg$fail(peg$c91); }
           }
         }
         if (s2 !== peg$FAILED) {
@@ -3920,7 +7502,7 @@ var parser=(function() {
         peg$currPos++;
       } else {
         s1 = peg$FAILED;
-        if (peg$silentFails === 0) { peg$fail(peg$c85); }
+        if (peg$silentFails === 0) { peg$fail(peg$c91); }
       }
       peg$silentFails--;
       if (s1 === peg$FAILED) {
@@ -3985,6 +7567,13 @@ var parser=(function() {
           pieces: result
         }
       }
+    function buildTree(head, tail, createNode) {
+        var result = head;
+        for (var i = 0, l = tail.length; i < l; i++) {
+          result = createNode(result, tail[i]);
+        }
+        return result;
+      }
 
     peg$result = peg$startRuleFunction();
 
diff --git a/quickcheck.js b/quickcheck.js
new file mode 100755
index 0000000..36c1c86
--- /dev/null
+++ b/quickcheck.js
@@ -0,0 +1,6 @@
+#!/usr/bin/env node
+
+const util = require('util')
+var parser = require("./" + process.argv[2])
+var parse = parser.parse || parser;
+process.stdout.write(JSON.stringify(parse(process.argv[3]), null, '  '))
diff --git a/tests/fixtures/shellcheck-tests/allspacing/ast.json b/tests/fixtures/shellcheck-tests/allspacing/ast.json
new file mode 100644
index 0000000..fe51488
--- /dev/null
+++ b/tests/fixtures/shellcheck-tests/allspacing/ast.json
@@ -0,0 +1 @@
+[]
diff --git a/tests/fixtures/shellcheck-tests/allspacing2/ast.json b/tests/fixtures/shellcheck-tests/allspacing2/ast.json
new file mode 100644
index 0000000..fe51488
--- /dev/null
+++ b/tests/fixtures/shellcheck-tests/allspacing2/ast.json
@@ -0,0 +1 @@
+[]
diff --git a/tests/fixtures/shellcheck-tests/allspacing3/ast.json b/tests/fixtures/shellcheck-tests/allspacing3/ast.json
new file mode 100644
index 0000000..fe51488
--- /dev/null
+++ b/tests/fixtures/shellcheck-tests/allspacing3/ast.json
@@ -0,0 +1 @@
+[]
diff --git a/tests/fixtures/shellcheck-tests/and-or/ast.json b/tests/fixtures/shellcheck-tests/and-or/ast.json
new file mode 100644
index 0000000..c22415b
--- /dev/null
+++ b/tests/fixtures/shellcheck-tests/and-or/ast.json
@@ -0,0 +1,43 @@
+[
+  {
+    "type": "command",
+    "command": {
+      "type": "literal",
+      "value": "grep"
+    },
+    "args": [
+      {
+        "type": "literal",
+        "value": "-i"
+      },
+      {
+        "type": "literal",
+        "value": "lol"
+      },
+      {
+        "type": "literal",
+        "value": "foo"
+      }
+    ],
+    "redirects": [],
+    "env": {},
+    "control": "||",
+    "next": {
+      "type": "command",
+      "command": {
+        "type": "literal",
+        "value": "exit"
+      },
+      "args": [
+        {
+          "type": "literal",
+          "value": "1"
+        }
+      ],
+      "redirects": [],
+      "env": {},
+      "control": ";",
+      "next": null
+    }
+  }
+]
diff --git a/tests/fixtures/shellcheck-tests/arithmetic-expression/source.sh b/tests/fixtures/shellcheck-tests/arithmetic-expression/source.sh
deleted file mode 100644
index 703a0db..0000000
--- a/tests/fixtures/shellcheck-tests/arithmetic-expression/source.sh
+++ /dev/null
@@ -1 +0,0 @@
-((a?b:c))
\ No newline at end of file
diff --git a/tests/fixtures/shellcheck-tests/arithmetic1/ast.json b/tests/fixtures/shellcheck-tests/arithmetic1/ast.json
new file mode 100644
index 0000000..d0d94d1
--- /dev/null
+++ b/tests/fixtures/shellcheck-tests/arithmetic1/ast.json
@@ -0,0 +1,29 @@
+[
+  {
+    "type": "arithmeticStatement",
+    "expression": {
+      "type": "arithmeticBinary",
+      "operator": "+",
+      "left": {
+        "type": "arithmeticUpdate",
+        "operator": "++",
+        "argument": {
+          "type": "variable",
+          "name": "n"
+        },
+        "prefix": false
+      },
+      "right": {
+        "type": "arithmeticUpdate",
+        "operator": "++",
+        "argument": {
+          "type": "variable",
+          "name": "c"
+        },
+        "prefix": true
+      }
+    },
+    "control": ";",
+    "next": null
+  }
+]
diff --git a/tests/fixtures/shellcheck-tests/arithmetic10/ast.json b/tests/fixtures/shellcheck-tests/arithmetic10/ast.json
new file mode 100644
index 0000000..e2fa118
--- /dev/null
+++ b/tests/fixtures/shellcheck-tests/arithmetic10/ast.json
@@ -0,0 +1,15 @@
+[
+  {
+    "type": "arithmeticStatement",
+    "expression": {
+      "type": "arithmeticUnary",
+      "operator": "!",
+      "argument": {
+        "type": "variable",
+        "name": "?"
+      }
+    },
+    "control": ";",
+    "next": null
+  }
+]
diff --git a/tests/fixtures/shellcheck-tests/arithmetic11/ast.json b/tests/fixtures/shellcheck-tests/arithmetic11/ast.json
new file mode 100644
index 0000000..e37377b
--- /dev/null
+++ b/tests/fixtures/shellcheck-tests/arithmetic11/ast.json
@@ -0,0 +1,19 @@
+[
+  {
+    "type": "arithmeticStatement",
+    "expression": {
+      "type": "arithmeticBinary",
+      "left": {
+        "type": "number",
+        "value": 8
+      },
+      "operator": "*",
+      "right": {
+        "type": "number",
+        "value": 15
+      }
+    },
+    "control": ";",
+    "next": null
+  }
+]
diff --git a/tests/fixtures/shellcheck-tests/arithmetic12/ast.json b/tests/fixtures/shellcheck-tests/arithmetic12/ast.json
new file mode 100644
index 0000000..d059078
--- /dev/null
+++ b/tests/fixtures/shellcheck-tests/arithmetic12/ast.json
@@ -0,0 +1,30 @@
+[
+  {
+    "type": "arithmeticStatement",
+    "expression": {
+      "type": "arithmeticBinary",
+      "operator": "+",
+      "left": {
+        "type": "arithmeticSubstitution",
+        "expression": {
+          "type": "arithmeticBinary",
+          "operator": "+",
+          "left": {
+            "type": "number",
+            "value": 3
+          },
+          "right": {
+            "type": "number",
+            "value": 2
+          }
+        }
+      },
+      "right": {
+        "type": "literal",
+        "value": "37"
+      }
+    },
+    "control": ";",
+    "next": null
+  }
+]
diff --git a/tests/fixtures/shellcheck-tests/arithmetic13/ast.json b/tests/fixtures/shellcheck-tests/arithmetic13/ast.json
new file mode 100644
index 0000000..fbb025d
--- /dev/null
+++ b/tests/fixtures/shellcheck-tests/arithmetic13/ast.json
@@ -0,0 +1,39 @@
+[
+  {
+    "type": "arithmeticStatement",
+    "expression": {
+      "type": "arithmeticUpdate",
+      "operator": "++",
+      "argument": {
+        "type": "arithmeticMemberExpression",
+        "array": {
+          "type": "variable",
+          "name": "foo"
+        },
+        "property": {
+          "type": "arithmeticBinary",
+          "operator": "+",
+          "left": {
+            "type": "arithmeticBinary",
+            "operator": "*",
+            "left": {
+              "type": "number",
+              "value": 9
+            },
+            "right": {
+              "type": "variable",
+              "name": "y"
+            }
+          },
+          "right": {
+            "type": "variable",
+            "name": "x"
+          }
+        }
+      },
+      "prefix": false
+    },
+    "control": ";",
+    "next": null
+  }
+]
diff --git a/tests/fixtures/shellcheck-tests/arithmetic14/ast.json b/tests/fixtures/shellcheck-tests/arithmetic14/ast.json
new file mode 100644
index 0000000..1292dfe
--- /dev/null
+++ b/tests/fixtures/shellcheck-tests/arithmetic14/ast.json
@@ -0,0 +1,37 @@
+[
+  {
+    "type": "arithmeticStatement",
+    "expression": {
+      "type": "arithmeticBinary",
+      "operator": "+",
+      "left": {
+        "type": "number",
+        "value": 1
+      },
+      "right": {
+        "type": "commandSubstitution",
+        "commands": [
+          {
+            "type": "command",
+            "command": {
+              "type": "literal",
+              "value": "echo"
+            },
+            "args": [
+              {
+                "type": "literal",
+                "value": "2"
+              }
+            ],
+            "redirects": [],
+            "env": {},
+            "control": ";",
+            "next": null
+          }
+        ]
+      }
+    },
+    "control": ";",
+    "next": null
+  }
+]
diff --git a/tests/fixtures/shellcheck-tests/arithmetic15/ast.json b/tests/fixtures/shellcheck-tests/arithmetic15/ast.json
new file mode 100644
index 0000000..66347f6
--- /dev/null
+++ b/tests/fixtures/shellcheck-tests/arithmetic15/ast.json
@@ -0,0 +1,73 @@
+[
+  {
+    "type": "arithmeticStatement",
+    "expression": {
+      "type": "arithmeticBinary",
+      "operator": "+",
+      "left": {
+        "type": "arithmeticMemberExpression",
+        "array": {
+          "type": "variable",
+          "name": "foo"
+        },
+        "property": {
+          "type": "arithmeticBinary",
+          "operator": "*",
+          "left": {
+            "type": "commandSubstitution",
+            "commands": [
+              {
+                "type": "command",
+                "command": {
+                  "type": "literal",
+                  "value": "echo"
+                },
+                "args": [
+                  {
+                    "type": "literal",
+                    "value": "foo"
+                  }
+                ],
+                "redirects": [
+                  {
+                    "type": "pipe",
+                    "command": {
+                      "type": "command",
+                      "command": {
+                        "type": "literal",
+                        "value": "sed"
+                      },
+                      "args": [
+                        {
+                          "type": "literal",
+                          "value": "s/foo/4/g"
+                        }
+                      ],
+                      "redirects": [],
+                      "env": {},
+                      "control": ";",
+                      "next": null
+                    }
+                  }
+                ],
+                "env": {},
+                "control": ";",
+                "next": null
+              }
+            ]
+          },
+          "right": {
+            "type": "number",
+            "value": 3
+          }
+        }
+      },
+      "right": {
+        "type": "number",
+        "value": 4
+      }
+    },
+    "control": ";",
+    "next": null
+  }
+]
diff --git a/tests/fixtures/shellcheck-tests/arithmetic16/ast.json b/tests/fixtures/shellcheck-tests/arithmetic16/ast.json
new file mode 100644
index 0000000..bfd6e93
--- /dev/null
+++ b/tests/fixtures/shellcheck-tests/arithmetic16/ast.json
@@ -0,0 +1,20 @@
+[
+  {
+    "type": "arithmeticStatement",
+    "expression": {
+      "type": "concatenation",
+      "pieces": [
+        {
+          "type": "variable",
+          "name": "foo"
+        },
+        {
+          "type": "variable",
+          "name": "bar"
+        }
+      ]
+    },
+    "control": ";",
+    "next": null
+  }
+]
diff --git a/tests/fixtures/shellcheck-tests/arithmetic17/ast.json b/tests/fixtures/shellcheck-tests/arithmetic17/ast.json
new file mode 100644
index 0000000..4503489
--- /dev/null
+++ b/tests/fixtures/shellcheck-tests/arithmetic17/ast.json
@@ -0,0 +1,35 @@
+[
+  {
+    "type": "arithmeticStatement",
+    "expression": {
+      "type": "arithmeticBinary",
+      "operator": "<",
+      "left": {
+        "type": "variable",
+        "name": "i"
+      },
+      "right": {
+        "type": "arithmeticBinary",
+        "operator": "+",
+        "left": {
+          "type": "number",
+          "value": 0
+        },
+        "right": {
+          "type": "arithmeticBinary",
+          "operator": "+",
+          "left": {
+            "type": "number",
+            "value": 1
+          },
+          "right": {
+            "type": "number",
+            "value": 1
+          }
+        }
+      }
+    },
+    "control": ";",
+    "next": null
+  }
+]
diff --git a/tests/fixtures/shellcheck-tests/arithmetic18/ast.json b/tests/fixtures/shellcheck-tests/arithmetic18/ast.json
new file mode 100644
index 0000000..3fea4e5
--- /dev/null
+++ b/tests/fixtures/shellcheck-tests/arithmetic18/ast.json
@@ -0,0 +1,22 @@
+[
+  {
+    "type": "arithmeticStatement",
+    "expression": {
+      "type": "arithmeticConditional",
+      "test": {
+        "type": "variable",
+        "name": "a"
+      },
+      "consequent": {
+        "type": "variable",
+        "name": "b"
+      },
+      "alternate": {
+        "type": "variable",
+        "name": "c"
+      }
+    },
+    "control": ";",
+    "next": null
+  }
+]
diff --git a/tests/fixtures/shellcheck-tests/arithmetic19/ast.json b/tests/fixtures/shellcheck-tests/arithmetic19/ast.json
new file mode 100644
index 0000000..e6f3a68
--- /dev/null
+++ b/tests/fixtures/shellcheck-tests/arithmetic19/ast.json
@@ -0,0 +1,19 @@
+[
+  {
+    "type": "arithmeticStatement",
+    "expression": {
+      "type": "arithmeticBinary",
+      "operator": "+",
+      "left": {
+        "type": "number",
+        "value": 3
+      },
+      "right": {
+        "type": "number",
+        "value": 2
+      }
+    },
+    "control": ";",
+    "next": null
+  }
+]
\ No newline at end of file
diff --git a/tests/fixtures/shellcheck-tests/arithmetic2/ast.json b/tests/fixtures/shellcheck-tests/arithmetic2/ast.json
new file mode 100644
index 0000000..a3c376a
--- /dev/null
+++ b/tests/fixtures/shellcheck-tests/arithmetic2/ast.json
@@ -0,0 +1,36 @@
+[
+  {
+    "type": "arithmeticStatement",
+    "expression": {
+      "type": "arithmeticBinary",
+      "operator": "-",
+      "left": {
+        "type": "arithmeticBinary",
+        "operator": "*",
+        "left": {
+          "type": "variable",
+          "name": "N"
+        },
+        "right": {
+          "type": "number",
+          "value": 4
+        }
+      },
+      "right": {
+        "type": "arithmeticSequence",
+        "expressions": [
+          {
+            "type": "number",
+            "value": 3
+          },
+          {
+            "type": "number",
+            "value": 2
+          }
+        ]
+      }
+    },
+    "control": ";",
+    "next": null
+  }
+]
diff --git a/tests/fixtures/shellcheck-tests/arithmetic20/ast.json b/tests/fixtures/shellcheck-tests/arithmetic20/ast.json
new file mode 100644
index 0000000..1420dda
--- /dev/null
+++ b/tests/fixtures/shellcheck-tests/arithmetic20/ast.json
@@ -0,0 +1,33 @@
+[
+  {
+    "type": "arithmeticStatement",
+    "expression": {
+      "type": "arithmeticConditional",
+      "test": {
+        "type": "variable",
+        "name": "a"
+      },
+      "consequent": {
+        "type": "arithmeticConditional",
+        "test": {
+          "type": "variable",
+          "name": "b"
+        },
+        "consequent": {
+          "type": "variable",
+          "name": "c"
+        },
+        "alternate": {
+          "type": "variable",
+          "name": "d"
+        }
+      },
+      "alternate": {
+        "type": "variable",
+        "name": "e"
+      }
+    },
+    "control": ";",
+    "next": null
+  }
+]
diff --git a/tests/fixtures/shellcheck-tests/arithmetic21/ast.json b/tests/fixtures/shellcheck-tests/arithmetic21/ast.json
new file mode 100644
index 0000000..d8871b1
--- /dev/null
+++ b/tests/fixtures/shellcheck-tests/arithmetic21/ast.json
@@ -0,0 +1,33 @@
+[
+  {
+    "type": "arithmeticStatement",
+    "expression": {
+      "type": "arithmeticConditional",
+      "test": {
+        "type": "variable",
+        "name": "a"
+      },
+      "consequent": {
+        "type": "variable",
+        "name": "b"
+      },
+      "alternate": {
+        "type": "arithmeticConditional",
+        "test": {
+          "type": "variable",
+          "name": "c"
+        },
+        "consequent": {
+          "type": "variable",
+          "name": "d"
+        },
+        "alternate": {
+          "type": "variable",
+          "name": "e"
+        }
+      }
+    },
+    "control": ";",
+    "next": null
+  }
+]
diff --git a/tests/fixtures/shellcheck-tests/arithmetic22/ast.json b/tests/fixtures/shellcheck-tests/arithmetic22/ast.json
new file mode 100644
index 0000000..81dbb95
--- /dev/null
+++ b/tests/fixtures/shellcheck-tests/arithmetic22/ast.json
@@ -0,0 +1,19 @@
+[
+  {
+    "type": "arithmeticStatement",
+    "expression": {
+      "type": "arithmeticUnary",
+      "operator": "!",
+      "argument": {
+        "type": "arithmeticUnary",
+        "operator": "!",
+        "argument": {
+          "type": "variable",
+          "name": "a"
+        }
+      }
+    },
+    "control": ";",
+    "next": null
+  }
+]
diff --git a/tests/fixtures/shellcheck-tests/arithmetic3/ast.json b/tests/fixtures/shellcheck-tests/arithmetic3/ast.json
new file mode 100644
index 0000000..7895898
--- /dev/null
+++ b/tests/fixtures/shellcheck-tests/arithmetic3/ast.json
@@ -0,0 +1,27 @@
+[
+  {
+    "type": "arithmeticStatement",
+    "expression": {
+      "type": "arithmeticAssignment",
+      "left": {
+        "type": "variable",
+        "name": "n"
+      },
+      "operator": "|=",
+      "right": {
+        "type": "arithmeticBinary",
+        "operator": "<<",
+        "left": {
+          "type": "number",
+          "value": 2
+        },
+        "right": {
+          "type": "number",
+          "value": 1
+        }
+      }
+    },
+    "control": ";",
+    "next": null
+  }
+]
diff --git a/tests/fixtures/shellcheck-tests/arithmetic4/ast.json b/tests/fixtures/shellcheck-tests/arithmetic4/ast.json
new file mode 100644
index 0000000..4b77d73
--- /dev/null
+++ b/tests/fixtures/shellcheck-tests/arithmetic4/ast.json
@@ -0,0 +1,27 @@
+[
+  {
+    "type": "arithmeticStatement",
+    "expression": {
+      "type": "arithmeticAssignment",
+      "left": {
+        "type": "variable",
+        "name": "n"
+      },
+      "operator": "&=",
+      "right": {
+        "type": "arithmeticBinary",
+        "operator": "**",
+        "left": {
+          "type": "number",
+          "value": 2
+        },
+        "right": {
+          "type": "number",
+          "value": 3
+        }
+      }
+    },
+    "control": ";",
+    "next": null
+  }
+]
diff --git a/tests/fixtures/shellcheck-tests/arithmetic5/.error.json b/tests/fixtures/shellcheck-tests/arithmetic5/.error.json
new file mode 100644
index 0000000..66c96cc
--- /dev/null
+++ b/tests/fixtures/shellcheck-tests/arithmetic5/.error.json
@@ -0,0 +1,3 @@
+{
+  "bash_message": "attempted assignment to non-variable"
+}
diff --git a/tests/fixtures/shellcheck-tests/arithmetic5/ast.json b/tests/fixtures/shellcheck-tests/arithmetic5/ast.json
new file mode 100644
index 0000000..c9c5935
--- /dev/null
+++ b/tests/fixtures/shellcheck-tests/arithmetic5/ast.json
@@ -0,0 +1,35 @@
+[
+  {
+    "type": "arithmeticStatement",
+    "expression": {
+      "type": "arithmeticAssignment",
+      "left": {
+        "type": "number",
+        "value": 1
+      },
+      "operator": "|=",
+      "right": {
+        "type": "arithmeticAssignment",
+        "left": {
+          "type": "arithmeticLogical",
+          "operator": "&&",
+          "left": {
+            "type": "number",
+            "value": 4
+          },
+          "right": {
+            "type": "variable",
+            "name": "n"
+          }
+        },
+        "operator": ">>=",
+        "right": {
+          "type": "number",
+          "value": 4
+        }
+      }
+    },
+    "control": ";",
+    "next": null
+  }
+]
diff --git a/tests/fixtures/shellcheck-tests/arithmetic6/ast.json b/tests/fixtures/shellcheck-tests/arithmetic6/ast.json
new file mode 100644
index 0000000..d9936c4
--- /dev/null
+++ b/tests/fixtures/shellcheck-tests/arithmetic6/ast.json
@@ -0,0 +1,35 @@
+[
+  {
+    "type": "arithmeticStatement",
+    "expression": {
+      "type": "arithmeticLogical",
+      "operator": "||",
+      "left": {
+        "type": "arithmeticBinary",
+        "operator": "|",
+        "left": {
+          "type": "number",
+          "value": 1
+        },
+        "right": {
+          "type": "number",
+          "value": 2
+        }
+      },
+      "right": {
+        "type": "arithmeticBinary",
+        "operator": "|",
+        "left": {
+          "type": "number",
+          "value": 3
+        },
+        "right": {
+          "type": "number",
+          "value": 4
+        }
+      }
+    },
+    "control": ";",
+    "next": null
+  }
+]
diff --git a/tests/fixtures/shellcheck-tests/arithmetic7/ast.json b/tests/fixtures/shellcheck-tests/arithmetic7/ast.json
new file mode 100644
index 0000000..5bffb8e
--- /dev/null
+++ b/tests/fixtures/shellcheck-tests/arithmetic7/ast.json
@@ -0,0 +1,27 @@
+[
+  {
+    "type": "arithmeticStatement",
+    "expression": {
+      "type": "arithmeticBinary",
+      "operator": "*",
+      "left": {
+        "type": "number",
+        "value": 3
+      },
+      "right": {
+        "type": "arithmeticBinary",
+        "operator": "**",
+        "left": {
+          "type": "number",
+          "value": 2
+        },
+        "right": {
+          "type": "number",
+          "value": 10
+        }
+      }
+    },
+    "control": ";",
+    "next": null
+  }
+]
diff --git a/tests/fixtures/shellcheck-tests/arithmetic8/ast.json b/tests/fixtures/shellcheck-tests/arithmetic8/ast.json
new file mode 100644
index 0000000..5010a8e
--- /dev/null
+++ b/tests/fixtures/shellcheck-tests/arithmetic8/ast.json
@@ -0,0 +1,11 @@
+[
+  {
+    "type": "arithmeticStatement",
+    "expression": {
+      "type": "number",
+      "value": 3
+    },
+    "control": ";",
+    "next": null
+  }
+]
diff --git a/tests/fixtures/shellcheck-tests/arithmetic9/ast.json b/tests/fixtures/shellcheck-tests/arithmetic9/ast.json
new file mode 100644
index 0000000..8e9d0a7
--- /dev/null
+++ b/tests/fixtures/shellcheck-tests/arithmetic9/ast.json
@@ -0,0 +1,27 @@
+[
+  {
+    "type": "arithmeticStatement",
+    "expression": {
+      "type": "arithmeticBinary",
+      "operator": "^",
+      "left": {
+        "type": "variable",
+        "name": "a"
+      },
+      "right": {
+        "type": "arithmeticUnary",
+        "operator": "!",
+        "argument": {
+          "type": "arithmeticUnary",
+          "operator": "-",
+          "argument": {
+            "type": "variable",
+            "name": "b"
+          }
+        }
+      }
+    },
+    "control": ";",
+    "next": null
+  }
+]
diff --git a/tests/shellcheck-fixtures.js b/tests/shellcheck-fixtures.js
index 439f4cd..faa20ad 100644
--- a/tests/shellcheck-fixtures.js
+++ b/tests/shellcheck-fixtures.js
@@ -24,12 +24,13 @@ test('shellcheck fixtures', function(t) {
 
   t.plan(fixtureDirs.length)
   fixtureDirs.forEach(function (fixtureDir) {
+    var fixtureName = fixtureDir.replace(fixturesDir + '/', '')
     var source = fs.readFileSync(path.join(fixtureDir, 'source.sh'), 'utf8')
 
     var error, ast;
-    try { error = require(path.join(fixtureDir, 'error.json')) } catch (e) {}
+    try { error = require(path.resolve(fixtureDir, 'error.json')) } catch (e) {}
     if (!error) {
-      try { ast = require(path.join(fixtureDir, 'ast.json')) } catch (e) {}
+      try { ast = require(path.resolve(fixtureDir, 'ast.json')) } catch (e) {}
     }
 
     if (error) {
@@ -37,15 +38,19 @@ test('shellcheck fixtures', function(t) {
         parse(source)
       }, error.message ? new RegExp(error.message) : undefined, fixtureDir + ' errored')
     } else if (ast) {
-      t.deepEqual(parse(source), ast, dir)
+      t.deepEqual(parse(source), ast, fixtureName)
     } else {
       try {
-        parse(source)
-        t.pass(fixtureDir.replace(fixturesDir + '/', '') + ': parsed sucessfully')
+        ast = parse(source)
+        if (process.env.write_shellcheck_fixture_ast) {
+          fs.writeFileSync(path.join(fixtureDir, 'ast.json'), JSON.stringify(ast, null, '  ') + '\n', 'utf8')
+        }
+        t.pass(fixtureName + ': parsed sucessfully')
       } catch (e) {
         if (e instanceof parse.SyntaxError) {
-          t.fail('parse failed')
-          formatParseError(fixtureDir, source, e)
+          var formattedErr = formatParseError(fixtureDir, source, e)
+          t.fail('parse failed: ' + formattedErr)
+          console.error(formattedErr + '\n' + e.stack)
         } else {
           throw e
         }
@@ -63,5 +68,5 @@ function formatParseError (dir, source, err) {
   msg += '\n  ' + source.slice(start, start + 10).trim() + '\n'
   for (var i = 0; i <= (err.column - start); i++) msg += '-';
   msg += '^'
-  console.error(msg)
+  return msg
 }