src/HOL/Relation.thy
changeset 47937 70375fa2679d
parent 47436 d8fad618a67a
child 48253 4410a709913c
equal deleted inserted replaced
47936:756f30eac792 47937:70375fa2679d
   171 lemma reflpE:
   171 lemma reflpE:
   172   assumes "reflp r"
   172   assumes "reflp r"
   173   obtains "r x x"
   173   obtains "r x x"
   174   using assms by (auto dest: refl_onD simp add: reflp_def)
   174   using assms by (auto dest: refl_onD simp add: reflp_def)
   175 
   175 
       
   176 lemma reflpD:
       
   177   assumes "reflp r"
       
   178   shows "r x x"
       
   179   using assms by (auto elim: reflpE)
       
   180 
   176 lemma refl_on_Int: "refl_on A r ==> refl_on B s ==> refl_on (A \<inter> B) (r \<inter> s)"
   181 lemma refl_on_Int: "refl_on A r ==> refl_on B s ==> refl_on (A \<inter> B) (r \<inter> s)"
   177   by (unfold refl_on_def) blast
   182   by (unfold refl_on_def) blast
   178 
   183 
   179 lemma reflp_inf:
   184 lemma reflp_inf:
   180   "reflp r \<Longrightarrow> reflp s \<Longrightarrow> reflp (r \<sqinter> s)"
   185   "reflp r \<Longrightarrow> reflp s \<Longrightarrow> reflp (r \<sqinter> s)"