stableUnfoldingVars :: Unfolding -> Maybe VarSet
stableUnfoldingVars unf = fvVarSet `fmap` stableUnfoldingFVs unf
stableUnfoldingVars :: Unfolding -> Maybe VarSet
stableUnfoldingVars unf = fvVarSet `fmap` stableUnfoldingFVs unf
stableUnfoldingVars unf = fvVarSet `fmap` stableUnfoldingFVs unf