--- a/NEWS Wed Nov 23 10:27:24 2022 +0100
+++ b/NEWS Thu Nov 24 10:02:26 2022 +0100
@@ -38,6 +38,8 @@
- Added lemmas.
antisym_if_asymp
antisymp_if_asymp
+ asym_if_irrefl_and_trans
+ asymp_if_irreflp_and_transp
irrefl_onD
irrefl_onI
irrefl_on_converse[simp]
--- a/src/HOL/Relation.thy Wed Nov 23 10:27:24 2022 +0100
+++ b/src/HOL/Relation.thy Thu Nov 24 10:02:26 2022 +0100
@@ -561,6 +561,12 @@
lemma transp_singleton [simp]: "transp (\<lambda>x y. x = a \<and> y = a)"
by (simp add: transp_def)
+lemma asym_if_irrefl_and_trans: "irrefl R \<Longrightarrow> trans R \<Longrightarrow> asym R"
+ by (auto intro: asymI dest: transD irreflD)
+
+lemma asymp_if_irreflp_and_transp: "irreflp R \<Longrightarrow> transp R \<Longrightarrow> asymp R"
+ by (rule asym_if_irrefl_and_trans[to_pred])
+
context preorder
begin