--- a/src/HOL/Auth/Guard/Guard_NS_Public.thy Thu Oct 13 15:38:32 2022 +0100
+++ b/src/HOL/Auth/Guard/Guard_NS_Public.thy Thu Oct 13 15:49:09 2022 +0100
@@ -64,7 +64,7 @@
by (auto simp: Gets_correct_def dest: nsp_has_no_Gets)
lemma nsp_is_one_step [iff]: "one_step nsp"
-by (unfold one_step_def, clarify, ind_cases "ev#evs \<in> nsp" for ev evs, auto)
+ unfolding one_step_def by (clarify, ind_cases "ev#evs \<in> nsp" for ev evs, auto)
lemma nsp_has_only_Says' [rule_format]: "evs \<in> nsp \<Longrightarrow>
ev \<in> set evs \<longrightarrow> (\<exists>A B X. ev=Says A B X)"