diff -r 3e3e7a68cd80 -r 6ad2c917dd2e src/HOL/Library/Cardinality.thy
--- a/src/HOL/Library/Cardinality.thy	Wed Oct 09 22:01:33 2024 +0200
+++ b/src/HOL/Library/Cardinality.thy	Wed Oct 09 23:38:29 2024 +0200
@@ -30,7 +30,7 @@
 
 subsection \<open>Cardinalities of types\<close>
 
-syntax "_type_card" :: "type => nat" (\<open>(1CARD/(1'(_')))\<close>)
+syntax "_type_card" :: "type => nat"  (\<open>(\<open>indent=1 notation=\<open>mixfix CARD\<close>\<close>CARD/(1'(_')))\<close>)
 
 syntax_consts "_type_card" == card