diff -r ff2a637a449e -r fc5066122e68 src/HOL/Metis_Examples/Message.thy
--- a/src/HOL/Metis_Examples/Message.thy	Fri Oct 18 11:44:05 2024 +0200
+++ b/src/HOL/Metis_Examples/Message.thy	Fri Oct 18 14:20:09 2024 +0200
@@ -50,6 +50,8 @@
 text\<open>Concrete syntax: messages appear as \<open>\<lbrace>A,B,NA\<rbrace>\<close>, etc...\<close>
 syntax
   "_MTuple" :: "['a, args] \<Rightarrow> 'a * 'b"  (\<open>(\<open>indent=2 notation=\<open>mixfix message tuple\<close>\<close>\<lbrace>_,/ _\<rbrace>)\<close>)
+syntax_consts
+  "_MTuple" \<rightleftharpoons> MPair
 translations
   "\<lbrace>x, y, z\<rbrace>" \<rightleftharpoons> "\<lbrace>x, \<lbrace>y, z\<rbrace>\<rbrace>"
   "\<lbrace>x, y\<rbrace>" \<rightleftharpoons> "CONST MPair x y"