tcView :: Type -> Maybe Type
-- ^ Similar to 'coreView', but for the type checker, which just looks through synonyms
tcView (TyConApp tc tys) | Just (tenv, rhs, tys') <- tcExpandTyCon_maybe tc tys
                         = Just (mkAppTys (substTy (mkTopTvSubst tenv) rhs) tys')
tcView :: Type -> Maybe Type
tcView (TyConApp tc tys) | Just (tenv, rhs, tys') <- tcExpandTyCon_maybe tc tys
                         = Just (mkAppTys (substTy (mkTopTvSubst tenv) rhs) tys')
tcView (TyConApp tc tys) | Just (tenv, rhs, tys') <- tcExpandTyCon_maybe tc tys
                         = Just (mkAppTys (substTy (mkTopTvSubst tenv) rhs) tys')