<+> ptext (sLit "takes one argument")
tc_args arg2_ty' qtvs qtys [arg1_ty, arg2_ty]
= do { boxyUnify arg2_ty' (substTyWith qtvs qtys arg2_ty)
- ; arg1' <- tcArg lop 2 arg1 qtvs qtys arg1_ty
+ ; arg1' <- tcArg lop 1 arg1 qtvs qtys arg1_ty
; qtys' <- mapM refineBox qtys -- c.f. tcArgs
; return (qtys', arg1') }
tc_args _ _ _ _ = panic "tcExpr SectionL"