diff -r 66bff50bc5f1 -r fd21b4a93043 src/HOL/Nominal/Examples/Class1.thy
--- a/src/HOL/Nominal/Examples/Class1.thy	Fri Jun 18 15:03:12 2021 +0200
+++ b/src/HOL/Nominal/Examples/Class1.thy	Thu Jul 08 08:42:36 2021 +0200
@@ -1707,7 +1707,7 @@
   case (AndR c1 M c2 M' c3)
   then show ?case
     apply(auto simp add: fresh_prod calc_atm fresh_atm abs_fresh fresh_left)
-    apply (metis (erased, hide_lams))
+    apply (metis (erased, opaque_lifting))
     by metis
 next
   case AndL1