diff -r 56057198e4f5 -r 70c10dc41606 thys3/LexerSimp.thy
--- a/thys3/LexerSimp.thy	Fri May 26 08:09:30 2023 +0100
+++ b/thys3/LexerSimp.thy	Fri May 26 08:10:17 2023 +0100
@@ -2,7 +2,7 @@
   imports "Lexer" 
 begin
 
-section {* Lexer including some simplifications *}
+section \<open>Lexer including some simplifications\<close>
 
 
 fun F_RIGHT where