diff -r 46f59511b7bb -r d97fdabd9e2b src/HOL/Hoare/Hoare_Logic.thy
--- a/src/HOL/Hoare/Hoare_Logic.thy	Fri Sep 20 19:07:10 2024 +0200
+++ b/src/HOL/Hoare/Hoare_Logic.thy	Fri Sep 20 19:51:08 2024 +0200
@@ -27,7 +27,7 @@
 | Cond "'a bexp" "'a com" "'a com"
 | While "'a bexp" "'a com"
 
-abbreviation annskip ("SKIP") where "SKIP == Basic id"
+abbreviation annskip (\<open>SKIP\<close>) where "SKIP == Basic id"
 
 type_synonym 'a sem = "'a => 'a => bool"