diff -r e2ab4147b244 -r fa37ee54644c src/HOL/Hoare_Parallel/RG_Examples.thy
--- a/src/HOL/Hoare_Parallel/RG_Examples.thy	Tue Dec 03 22:46:24 2024 +0100
+++ b/src/HOL/Hoare_Parallel/RG_Examples.thy	Fri Dec 06 13:33:25 2024 +0100
@@ -117,11 +117,11 @@
     apply simp
    apply clarify
    apply simp
-   apply(subgoal_tac "xa=0")
+   apply(subgoal_tac "x=0")
     apply simp
    apply arith
   apply clarify
-  apply(case_tac xaa, simp, simp)
+  apply(case_tac xa, simp, simp)
  apply clarify
  apply simp
  apply(erule_tac x=0 in all_dupE)