src/HOL/Imperative_HOL/Ref.thy
changeset 67443 3abf6a722518
parent 63680 6e1e8b5abbfa
child 68224 1f7308050349
equal deleted inserted replaced
67442:f075640b8868 67443:3abf6a722518
    59 subsection \<open>Properties\<close>
    59 subsection \<open>Properties\<close>
    60 
    60 
    61 text \<open>Primitives\<close>
    61 text \<open>Primitives\<close>
    62 
    62 
    63 lemma noteq_sym: "r =!= s \<Longrightarrow> s =!= r"
    63 lemma noteq_sym: "r =!= s \<Longrightarrow> s =!= r"
    64   and unequal [simp]: "r \<noteq> r' \<longleftrightarrow> r =!= r'" \<comment> "same types!"
    64   and unequal [simp]: "r \<noteq> r' \<longleftrightarrow> r =!= r'" \<comment> \<open>same types!\<close>
    65   by (auto simp add: noteq_def)
    65   by (auto simp add: noteq_def)
    66 
    66 
    67 lemma noteq_irrefl: "r =!= r \<Longrightarrow> False"
    67 lemma noteq_irrefl: "r =!= r \<Longrightarrow> False"
    68   by (auto simp add: noteq_def)
    68   by (auto simp add: noteq_def)
    69 
    69