diff -r f27ba31b7e96 -r 6f7b9039715f Delete_prop.thy --- a/Delete_prop.thy Thu Dec 05 20:13:30 2013 +0800 +++ b/Delete_prop.thy Tue Dec 17 13:30:21 2013 +0800 @@ -229,6 +229,7 @@ "no_del_event s \ \ deleted obj s" by (induct s, simp, case_tac a,auto) + lemma nodel_exists_remains: "\no_del_event (s'@s); exists s obj\ \ exists (s'@s) obj" apply (drule_tac obj = obj in nodel_imp_un_deleted)