
diff -r b33803fcae2a -r ba2a92af88b4 src/HOL/Transitive_Closure.thy
--- a/src/HOL/Transitive_Closure.thy	Sat Jun 16 20:32:00 2018 +0200
+++ b/src/HOL/Transitive_Closure.thy	Sat Jun 16 22:09:24 2018 +0200
@@ -659,7 +659,7 @@
    apply (auto simp add: finite_Field)
   done
 
-lemma finite_rtrancl_Image: assumes "finite R" "finite A" shows "finite (R\<^sup>* `` A)"
+lemma finite_rtrancl_Image[simp]: assumes "finite R" "finite A" shows "finite (R\<^sup>* `` A)"
 proof (rule ccontr)
   assume "infinite (R\<^sup>* `` A)"
   with assms show False




