-tyConClass_maybe (AlgTyCon {algTcClass = maybe_clas}) = maybe_clas
-tyConClass_maybe ther_tycon = Nothing
+tyConClass_maybe (AlgTyCon {algTcParent = ClassTyCon clas}) = Just clas
+tyConClass_maybe ther_tycon = Nothing
+
+isFamInstTyCon :: TyCon -> Bool
+isFamInstTyCon (AlgTyCon {algTcParent = FamilyTyCon _}) = True
+isFamInstTyCon other_tycon = False
+
+tyConFamily_maybe :: TyCon -> Maybe TyCon
+tyConFamily_maybe (AlgTyCon {algTcParent = FamilyTyCon fam}) = Just fam
+tyConFamily_maybe ther_tycon = Nothing