Missing deepcopy in wp.py

[bensturgis]

In the method apply of the class ExpectationTransformer of the module wp, a deepcopy is missing in line 276 around expectation. Without this deepcopy, in the subsequent substitution, changes to one occurrence of this expectation are also applied to the other occurrences.
For example, the following code produces the output (5 + 2) + (5 + 2) instead of (5 + 2) + (4 + 2).

v = VarExpr('v')
a = SubstExpr({'x': NatLitExpr(5)}, v)
b = SubstExpr({'x': NatLitExpr(4)}, v)
e = BinopExpr(Binop.PLUS, a, b)
wt = WeightingTransformer('v', e)
print(wt.apply(BinopExpr(Binop.PLUS, VarExpr('x'), NatLitExpr(2))))

[Philipp15b]

WeightingTransformer is not a part of probably. Could you provide a minimal working example that works only with probably APIs? Thanks!

[bensturgis]

Sorry, I meant ExpectationTransformer. A working example is given by

v = VarExpr('v')
a = SubstExpr({'x': NatLitExpr(5)}, v)
b = SubstExpr({'x': NatLitExpr(4)}, v)
e = BinopExpr(Binop.PLUS, a, b)
wt = ExpectationTransformer('v', e)
print(wt.apply(BinopExpr(Binop.PLUS, VarExpr('x'), NatLitExpr(2))))

which produces the output (5 + 2) + (5 + 2) instead of (5 + 2) + (4 + 2).