--- a/src/ZF/Zorn.thy Tue Sep 27 17:54:20 2022 +0100
+++ b/src/ZF/Zorn.thy Tue Sep 27 18:02:34 2022 +0100
@@ -312,7 +312,7 @@
apply (rule ccontr)
apply (frule_tac z=z in chain_extend)
apply (assumption, blast)
-apply (unfold maxchain_def super_def)
+ unfolding maxchain_def super_def
apply (blast elim!: equalityCE)
done
@@ -346,7 +346,7 @@
"next \<in> increasing(S)
\<Longrightarrow> well_ord(TFin(S,next), Subset_rel(TFin(S,next)))"
apply (rule well_ordI)
-apply (unfold Subset_rel_def linear_def)
+ unfolding Subset_rel_def linear_def
txt\<open>Prove the well-foundedness goal\<close>
apply (rule wf_onI)
apply (frule well_ord_TFin_lemma, assumption)