idUnfoldingFVs :: Id -> FV
idUnfoldingFVs id = stableUnfoldingFVs (realIdUnfolding id) `orElse` emptyFV
idUnfoldingFVs :: Id -> FV
idUnfoldingFVs id = stableUnfoldingFVs (realIdUnfolding id) `orElse` emptyFV
idUnfoldingFVs id = stableUnfoldingFVs (realIdUnfolding id) `orElse` emptyFV