diff -r 60a788467639 -r 06aeb9054c07 src/HOL/Library/RBT_Set.thy
--- a/src/HOL/Library/RBT_Set.thy	Fri May 14 12:43:19 2021 +0100
+++ b/src/HOL/Library/RBT_Set.thy	Tue May 18 20:25:08 2021 +0100
@@ -790,7 +790,7 @@
       then show "x \<le> y"
         using Cons[symmetric]
         by(auto simp add: set_keys Cons_eq_filter_iff)
-          (metis sorted.simps(2) sorted_append sorted_keys)
+          (metis sorted_wrt.simps(2) sorted_append sorted_keys)
   qed
   thus ?thesis using Cons by (simp add: Bleast_def)
 qed