--- a/src/HOL/Set.thy Thu Oct 16 11:03:48 2025 +0200
+++ b/src/HOL/Set.thy Fri Oct 17 15:42:50 2025 +0100
@@ -1182,7 +1182,7 @@
by (fact bot_unique)
lemma not_psubset_empty [iff]: "\<not> (A < {})"
- by (fact not_less_bot) (* FIXME: already simp *)
+ by (fact not_less_bot) (*already simp *)
lemma Collect_subset [simp]: "{x\<in>A. P x} \<subseteq> A" by auto
@@ -1204,6 +1204,9 @@
lemma Collect_conj_eq: "{x. P x \<and> Q x} = {x. P x} \<inter> {x. Q x}"
by blast
+lemma Collect_conj_eq2: "{x \<in> A. P x \<and> Q x} = {x \<in> A. P x} \<inter> {x \<in> A. Q x}"
+ by blast
+
lemma Collect_mono_iff: "Collect P \<subseteq> Collect Q \<longleftrightarrow> (\<forall>x. P x \<longrightarrow> Q x)"
by blast