src/Pure/Syntax/syntax_ext.ML

--- a/src/Pure/Syntax/syntax_ext.ML	Fri Sep 20 11:19:23 2024 +0200
+++ b/src/Pure/Syntax/syntax_ext.ML	Fri Sep 20 13:30:55 2024 +0200
@@ -172,7 +172,7 @@
 val get_nat = get_property 0 1 (Value.parse_nat o #1);
 
 fun get_expression_markup ctxt =
-  get_property NONE (SOME (Markup.expression "")) (SOME o Markup_Expression.check ctxt)
+  get_property NONE (SOME Markup.expression0) (SOME o Markup_Expression.check ctxt)
     Markup.expressionN;
 
 end;