diff --git a/core/bench/Main.hs b/core/bench/Main.hs
index 8da6ec1..fec2cc6 100644
--- a/core/bench/Main.hs
+++ b/core/bench/Main.hs
@@ -20,11 +20,13 @@ main :: IO ()
 main = defaultMain benchmarks
 
 benchmarks :: [Benchmark]
-benchmarks = [ bgroup "clique" [clique n | n <- [5, 10, 25, 40]]
-             , bgroup "line"   [line   n | n <- [5, 10, 25, 40]]
-             , bgroup "loop"   [loop   n | n <- [50, 100, 500, 1000]]
-             , bgroup "tight"  [tight  n | n <- [50, 100, 500, 1000]]
-             , bgroup "parse"  [parse  n | n <- [50, 100, 500, 1000]]
+benchmarks = [ bgroup "clique"     [clique     n | n <- [5, 10, 25, 40]]
+             , bgroup "cliqueText" [cliqueText n | n <- [5, 10, 25, 40]]
+             , bgroup "line"       [line       n | n <- [5, 10, 25, 40]]
+             , bgroup "lineText"   [lineText   n | n <- [5, 10, 25, 40]]
+             , bgroup "loop"       [loop       n | n <- [50, 100, 500, 1000]]
+             , bgroup "tight"      [tight      n | n <- [50, 100, 500, 1000]]
+             , bgroup "parse"      [parse      n | n <- [50, 100, 500, 1000]]
              ]
 
 -- | Generate a complete graph of size @n@ and try to find a path from the first node to the last.
@@ -58,6 +60,21 @@ clique n = do
     let Right cfg = pdpConfigRules mempty path
     newHandle cfg {maxDepth = 4000}
 
+cliqueText :: Int -> Benchmark
+cliqueText n = do
+  let path = [rls| path(?x, ?y) :- application says edge(?x, ?y).
+                   path(?x, ?z) :- path(?x, ?y), path(?y, ?z). |]
+      edges = [lit "edge" [val . pack $ show x, val . pack $ show y]
+                 | x <- [1..n]
+                 , y <- [1..n]]
+      go hdl = bench (show n) $ whnfIO $ do
+        res <- checkQuery hdl edges "path" [val $ pack "1", val . pack $ show n]
+        either (error . show) (bool (error "no path found") (pure True)) res
+
+  flip env go $ do
+    let Right cfg = pdpConfigRules mempty path
+    newHandle cfg {maxDepth = 4000}
+
 -- | Generates a linear sequence of @n@ facts and tries to find a path from the first node to the
 -- last.  It uses a cons-list shaped @path@ rule.  The @application@ assertion looks like this:
 --
@@ -81,6 +98,20 @@ line n = do
     let Right cfg = pdpConfigRules mempty path
     newHandle cfg {maxDepth = 4000}
 
+lineText :: Int -> Benchmark
+lineText n = do
+  let path = [rls| path(?x, ?y) :- application says edge(?x, ?y).
+                   path(?x, ?z) :- application says edge(?x, ?y), path(?y, ?z). |]
+      edges = [lit "edge" [val . pack $ show x, val . pack $ show y]
+                 | (x, y) <- zip [1..pred n] [2..n]]
+      go hdl = bench (show n) $ whnfIO $ do
+        res <- checkQuery hdl edges "path" [val $ pack "1", val . pack $ show n]
+        either (error . show) (bool (error "no path found") (pure True)) res
+
+  flip env go $ do
+    let Right cfg = pdpConfigRules mempty path
+    newHandle cfg {maxDepth = 4000}
+
 -- | Generates a loop of five rules (@e@ implies @d@ implies @c@ implies @b@ implies @a@ implies
 -- @e@), each of arity 4 (so that the benchmark exercises the unification code), and then runs a
 -- query with @n@ fuel.
diff --git a/core/package.yaml b/core/package.yaml
index 74729a6..d687743 100644
--- a/core/package.yaml
+++ b/core/package.yaml
@@ -10,6 +10,7 @@ library:
     - deepseq
     - filepath
     - hashable
+    - intern
     - megaparsec
     - mtl
     - qq-literals
diff --git a/core/src/Language/Avaleryar/ModeCheck.hs b/core/src/Language/Avaleryar/ModeCheck.hs
index 5b22892..db3197f 100644
--- a/core/src/Language/Avaleryar/ModeCheck.hs
+++ b/core/src/Language/Avaleryar/ModeCheck.hs
@@ -27,7 +27,7 @@ data ModeError
   | FVModeRestricted RawVar
   | FVInAssertionPosition RawVar
   | FVInRuleHead RawVar
-    deriving (Eq, Ord, Read, Show)
+    deriving (Eq, Ord, Show)
 
 instance Pretty ModeError where
   pretty (UnboundNativeAssertion assn)        = "unbound native assertion: " <> squotes (pretty assn)
diff --git a/core/src/Language/Avaleryar/PDP.hs b/core/src/Language/Avaleryar/PDP.hs
index 488ba34..3f5a54a 100644
--- a/core/src/Language/Avaleryar/PDP.hs
+++ b/core/src/Language/Avaleryar/PDP.hs
@@ -50,7 +50,7 @@ data PDPError
   | VarInQueryResults TextVar
   | ParseError String
   | SubmitError SubmitError
-    deriving (Eq, Ord, Read, Show, Typeable)
+    deriving (Eq, Ord, Show, Typeable)
 
 instance Exception PDPError
 
diff --git a/core/src/Language/Avaleryar/Parser.hs b/core/src/Language/Avaleryar/Parser.hs
index ea18ced..a84435a 100644
--- a/core/src/Language/Avaleryar/Parser.hs
+++ b/core/src/Language/Avaleryar/Parser.hs
@@ -19,6 +19,7 @@ module Language.Avaleryar.Parser
 import           Control.Monad              (void)
 import           Data.Bifunctor             (first)
 import           Data.Either                (partitionEithers)
+import qualified Data.Interned              as Interned
 import           Data.Text                  (Text)
 import qualified Data.Text                  as T
 import qualified Data.Text.IO               as T
@@ -65,9 +66,9 @@ sym = lexeme (T.pack <$> go) <?> "symbol"
 
 value :: Parser Value
 value =     I <$> L.signed (pure ()) L.decimal
-        <|> T <$> stringLiteral
-        <|> T <$> sym -- unquoted symbols
-        <|> B <$> (string "#t" *> pure True <|> string "#f" *> pure False) 
+        <|> T <$> fmap Interned.intern stringLiteral
+        <|> T <$> fmap Interned.intern sym -- unquoted symbols
+        <|> B <$> (string "#t" *> pure True <|> string "#f" *> pure False)
 
 ident :: Parser Text
 ident = sym <?> "identifer"
@@ -183,4 +184,3 @@ qry = qqLiteral queryQQParser 'queryQQParser
 
 fct :: QuasiQuoter
 fct = qqLiteral factQQParser 'factQQParser
-
diff --git a/core/src/Language/Avaleryar/Semantics.hs b/core/src/Language/Avaleryar/Semantics.hs
index 6b1e3b5..1ab4b83 100644
--- a/core/src/Language/Avaleryar/Semantics.hs
+++ b/core/src/Language/Avaleryar/Semantics.hs
@@ -71,6 +71,8 @@ import           Control.Monad.Except
 import           Control.Monad.State
 import           Data.Foldable
 import qualified Data.HashSet                 as HashSet
+import qualified Data.Interned                as Interned
+import qualified Data.Interned.Internal.Text  as Interned
 import           Data.Map                     (Map)
 import qualified Data.Map                     as Map
 import           Data.Maybe
@@ -349,10 +351,10 @@ compileQuery' :: String -> Query -> Avaleryar (Lit EVar)
 compileQuery' assn (Lit (Pred p _) args) = compileQuery assn p args
 
 insertRuleAssertion :: Text -> Map Pred (Lit EVar -> Avaleryar ()) -> RulesDb -> RulesDb
-insertRuleAssertion assn rules = RulesDb . Map.insert (T assn) rules . unRulesDb
+insertRuleAssertion assn rules = RulesDb . Map.insert (toValue assn) rules . unRulesDb
 
 retractRuleAssertion :: Text -> RulesDb -> RulesDb
-retractRuleAssertion assn = RulesDb . Map.delete (T assn) . unRulesDb
+retractRuleAssertion assn = RulesDb . Map.delete (toValue assn) . unRulesDb
 
 ---------------------
 
diff --git a/core/src/Language/Avaleryar/Syntax.hs b/core/src/Language/Avaleryar/Syntax.hs
index 674e0f5..7778d57 100644
--- a/core/src/Language/Avaleryar/Syntax.hs
+++ b/core/src/Language/Avaleryar/Syntax.hs
@@ -45,11 +45,13 @@ name of the assertion in which @may\/1@ is defined).  In brief:
 
 module Language.Avaleryar.Syntax where
 
-import           Control.DeepSeq              (NFData)
+import           Control.DeepSeq              (NFData(rnf))
 import           Data.Char                    (isSpace)
 import           Data.Function                (on)
 import           Data.Functor.Const           (Const(..))
 import           Data.Hashable                (Hashable(hashWithSalt))
+import qualified Data.Interned                as Interned
+import qualified Data.Interned.Internal.Text  as Interned
 import           Data.Map                     (Map)
 import           Data.String
 import           Data.Text                    (Text)
@@ -62,11 +64,15 @@ import           Text.PrettyPrint.Leijen.Text
 
 data Value
   = I Int
-  | T Text
+  | T Interned.InternedText
   | B Bool
-    deriving (Eq, Ord, Read, Show, Generic)
+    deriving (Eq, Ord, Show, Generic)
+
+instance NFData Value where
+  rnf (I i) = rnf i
+  rnf (T t) = rnf (Interned.unintern t)
+  rnf (B b) = rnf b
 
-instance NFData Value
 instance Hashable Value
 
 instance IsString Value where
@@ -75,12 +81,12 @@ instance IsString Value where
 instance Pretty Value where
   pretty (I n) = pretty n
   pretty (B b) = if b then "#t" else "#f"
-  pretty (T t) = if T.any isSpace t
-                 then pretty (show t) -- want the quotes/escaping
-                 else pretty t        -- display as a symbol
+  pretty (T t) = if T.any isSpace (Interned.unintern t)
+                 then pretty (show $ Interned.unintern t) -- want the quotes/escaping
+                 else pretty (Interned.unintern t)        -- display as a symbol
 
 -- | A predicate is identified by its name and arity (i.e., the predicate of the literal @foo(bar, ?baz)@ is @foo/2@)
-data Pred = Pred Text Int deriving (Eq, Ord, Read, Show, Generic)
+data Pred = Pred Text Int deriving (Eq, Ord, Show, Generic)
 
 instance NFData Pred
 instance Hashable Pred
@@ -92,7 +98,7 @@ instance Pretty Pred where
 -- provide a bit of safety by keeping us from crossing various streams (e.g., separating runtime
 -- unification variables from raw variables straight out of the parser helps avoid a bit of unwanted
 -- variable capture).
-data Term v = Val Value | Var v deriving (Eq, Ord, Read, Show, Functor, Foldable, Traversable, Generic)
+data Term v = Val Value | Var v deriving (Eq, Ord, Show, Functor, Foldable, Traversable, Generic)
 
 instance NFData v => NFData (Term v)
 instance Hashable v => Hashable (Term v)
@@ -103,7 +109,7 @@ instance Pretty v => Pretty (Term v) where
 
 -- | A literal is identified by a 'Pred' and a list of 'Term's, where the arity in the 'Pred' is the
 -- same as the length of the list of 'Term's in the argument list.
-data Lit v = Lit Pred [Term v] deriving (Eq, Ord, Read, Show, Functor, Foldable, Traversable, Generic)
+data Lit v = Lit Pred [Term v] deriving (Eq, Ord, Show, Functor, Foldable, Traversable, Generic)
 
 instance NFData v => NFData (Lit v)
 instance Hashable v => Hashable (Lit v)
@@ -117,7 +123,7 @@ lit pn as = Lit (Pred pn (length as)) as
 
 -- | A reference to an assertion may either statically denote a native assertion or appear as a
 -- 'Term'.
-data ARef v = ARNative Text | ARTerm (Term v) | ARCurrent deriving (Eq, Ord, Read, Show, Functor, Foldable, Traversable, Generic)
+data ARef v = ARNative Text | ARTerm (Term v) | ARCurrent deriving (Eq, Ord, Show, Functor, Foldable, Traversable, Generic)
 
 instance NFData v => NFData (ARef v)
 instance Hashable v => Hashable (ARef v)
@@ -136,7 +142,7 @@ prettyAssertion assn ps = pretty assn
 -- When no assertion appears in the concrete syntax, the parser inserts a reference to the assertion
 -- currently being parsed.
 data BodyLit v = Says (ARef v) (Lit v)
-  deriving (Eq, Ord, Read, Show, Functor, Foldable, Traversable, Generic)
+  deriving (Eq, Ord, Show, Functor, Foldable, Traversable, Generic)
 
 instance NFData v => NFData (BodyLit v)
 instance Hashable v => Hashable (BodyLit v)
@@ -146,7 +152,7 @@ instance Pretty v => Pretty (BodyLit v) where
 
 -- | A rule has a head and a body made of 'BodyLit's.
 data Rule v = Rule (Lit v) [BodyLit v]
-  deriving (Eq, Ord, Read, Show, Functor, Foldable, Traversable, Generic)
+  deriving (Eq, Ord, Show, Functor, Foldable, Traversable, Generic)
 
 instance NFData v => NFData (Rule v)
 instance Hashable v => Hashable (Rule v)
@@ -265,8 +271,8 @@ instance Valuable Value where
   fromValue = Just
 
 instance Valuable Text where
-  toValue = T
-  fromValue (T a) = Just a
+  toValue = T . Interned.intern
+  fromValue (T a) = Just (Interned.unintern a)
   fromValue _     = Nothing
 
 instance Valuable Int  where
diff --git a/core/src/Language/Avaleryar/Testing.hs b/core/src/Language/Avaleryar/Testing.hs
index 3297a0c..e382083 100644
--- a/core/src/Language/Avaleryar/Testing.hs
+++ b/core/src/Language/Avaleryar/Testing.hs
@@ -53,6 +53,7 @@ module Language.Avaleryar.Testing
 
 import           Data.Bool                    (bool)
 import           Data.Foldable                (for_, toList)
+import qualified Data.Interned                as Interned
 import qualified Data.Map                     as Map
 import           Data.Text                    (Text, splitOn)
 import           Data.Void                    (vacuous)
@@ -93,9 +94,9 @@ parseTestCase (Directive (Lit (Pred "test" _) (tn:dbs)) tqs) = do
 parseTestCase _ = Nothing
 
 parseDb :: (Text, Text) -> Directive -> Maybe TestDb
-parseDb (alias, assn) (Directive (Lit (Pred "db" _) [Val (T dbn)]) fs) | assn == dbn =
+parseDb (alias, assn) (Directive (Lit (Pred "db" _) [Val (T dbn)]) fs) | Interned.intern assn == dbn =
   Just ([(alias, fmap factToRule fs)], mempty)
-parseDb (alias, assn) (Directive (Lit (Pred "native" _) [Val (T dbn)]) fs) | assn == dbn =
+parseDb (alias, assn) (Directive (Lit (Pred "native" _) [Val (T dbn)]) fs) | Interned.intern assn == dbn =
   Just (mempty, mkNativeDb alias $ factsToNative fs)
 parseDb _ _ = Nothing
 
@@ -207,7 +208,3 @@ runTestFile conf k tf = do
   case parsed of
     Left err -> pure (Left err)
     Right ts -> Right <$> traverse gatherResults ts
-
-
-
-