--- a/src/Pure/Syntax/mixfix.ML Tue Oct 22 12:52:25 2024 +0200
+++ b/src/Pure/Syntax/mixfix.ML Tue Oct 22 13:39:24 2024 +0200
@@ -167,7 +167,11 @@
(* binder notation *)
val binder_stamp = stamp ();
-val binder_name = perhaps (try Lexicon.unmark_const) #> Lexicon.mark_binder;
+
+fun binder_name c =
+ (if Lexicon.is_const c then Lexicon.unmark_const c
+ else if Lexicon.is_fixed c then Lexicon.unmark_fixed c
+ else c) |> Lexicon.mark_binder;
val binder_bg = Symbol_Pos.explode0 "(";
val binder_en = Symbol_Pos.explode0 "_./ _)";