diff -r 079fe4292526 -r c7723cc15de8 src/HOL/Auth/Message.thy
--- a/src/HOL/Auth/Message.thy	Sun Aug 25 20:54:20 2024 +0200
+++ b/src/HOL/Auth/Message.thy	Sun Aug 25 21:10:01 2024 +0200
@@ -51,6 +51,8 @@
 text\<open>Concrete syntax: messages appear as \<open>\<lbrace>A,B,NA\<rbrace>\<close>, etc...\<close>
 syntax
   "_MTuple" :: "['a, args] \<Rightarrow> 'a * 'b"  ("(2\<lbrace>_,/ _\<rbrace>)")
+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"