diff -r 079fe4292526 -r c7723cc15de8 src/HOL/Algebra/Ring.thy
--- a/src/HOL/Algebra/Ring.thy	Sun Aug 25 20:54:20 2024 +0200
+++ b/src/HOL/Algebra/Ring.thy	Sun Aug 25 21:10:01 2024 +0200
@@ -46,6 +46,8 @@
 syntax
   "_finsum" :: "index \<Rightarrow> idt \<Rightarrow> 'a set \<Rightarrow> 'b \<Rightarrow> 'b"
       ("(3\<Oplus>__\<in>_. _)" [1000, 0, 51, 10] 10)
+syntax_consts
+  "_finsum" \<rightleftharpoons> finsum
 translations
   "\<Oplus>\<^bsub>G\<^esub>i\<in>A. b" \<rightleftharpoons> "CONST finsum G (\<lambda>i. b) A"
   \<comment> \<open>Beware of argument permutation!\<close>