--- a/src/HOL/Isar_Examples/Group_Notepad.thy Fri Sep 20 19:07:10 2024 +0200
+++ b/src/HOL/Isar_Examples/Group_Notepad.thy Fri Sep 20 19:51:08 2024 +0200
@@ -12,7 +12,7 @@
begin
txt \<open>hypothetical group axiomatization\<close>
- fix prod :: "'a \<Rightarrow> 'a \<Rightarrow> 'a" (infixl "\<odot>" 70)
+ fix prod :: "'a \<Rightarrow> 'a \<Rightarrow> 'a" (infixl \<open>\<odot>\<close> 70)
and one :: "'a"
and inverse :: "'a \<Rightarrow> 'a"
assume assoc: "(x \<odot> y) \<odot> z = x \<odot> (y \<odot> z)"