go (TyConApp tc tys) = go_tc tc tys
go (AppTy a b) = go a `plusNameEnv` go b
go (FunTy a b) = go a `plusNameEnv` go b
go (PredTy (IParam _ ty)) = go ty
go (PredTy (ClassP cls tys)) = go_tc (classTyCon cls) tys
go (ForAllTy _ ty) = go ty
go (TyConApp tc tys) = go_tc tc tys
go (AppTy a b) = go a `plusNameEnv` go b
go (FunTy a b) = go a `plusNameEnv` go b
go (PredTy (IParam _ ty)) = go ty
go (PredTy (ClassP cls tys)) = go_tc (classTyCon cls) tys
go (ForAllTy _ ty) = go ty