src/HOL/Relation.thy
changeset 76570 608489919ecf
parent 76560 df6ba3cf7874
child 76571 5a13f1519f5d
equal deleted inserted replaced
76560:df6ba3cf7874 76570:608489919ecf
   324   by (auto simp: irrefl_on_def)
   324   by (auto simp: irrefl_on_def)
   325 
   325 
   326 lemma irreflp_on_subset: "irreflp_on A R \<Longrightarrow> B \<subseteq> A \<Longrightarrow> irreflp_on B R"
   326 lemma irreflp_on_subset: "irreflp_on A R \<Longrightarrow> B \<subseteq> A \<Longrightarrow> irreflp_on B R"
   327   by (auto simp: irreflp_on_def)
   327   by (auto simp: irreflp_on_def)
   328 
   328 
   329 lemma (in preorder) irreflp_less[simp]: "irreflp (<)"
   329 lemma (in preorder) irreflp_on_less[simp]: "irreflp_on A (<)"
   330   by (simp add: irreflpI)
   330   by (simp add: irreflp_onI)
   331 
   331 
   332 lemma (in preorder) irreflp_greater[simp]: "irreflp (>)"
   332 lemma (in preorder) irreflp_on_greater[simp]: "irreflp_on A (>)"
   333   by (simp add: irreflpI)
   333   by (simp add: irreflp_onI)
   334 
   334 
   335 subsubsection \<open>Asymmetry\<close>
   335 subsubsection \<open>Asymmetry\<close>
   336 
   336 
   337 inductive asym :: "'a rel \<Rightarrow> bool"
   337 inductive asym :: "'a rel \<Rightarrow> bool"
   338   where asymI: "(\<And>a b. (a, b) \<in> R \<Longrightarrow> (b, a) \<notin> R) \<Longrightarrow> asym R"
   338   where asymI: "(\<And>a b. (a, b) \<in> R \<Longrightarrow> (b, a) \<notin> R) \<Longrightarrow> asym R"