src/HOL/Option.thy
changeset 57123 b5324647e0f1
parent 57091 1fa9c19ba2c9
child 58112 8081087096ad
equal deleted inserted replaced
57122:5f69b8c3af5a 57123:b5324647e0f1
     9 begin
     9 begin
    10 
    10 
    11 datatype_new 'a option =
    11 datatype_new 'a option =
    12     None
    12     None
    13   | Some (the: 'a)
    13   | Some (the: 'a)
       
    14 
    14 datatype_compat option
    15 datatype_compat option
    15 
    16 
    16 lemma [case_names None Some, cases type: option]:
    17 lemma [case_names None Some, cases type: option]:
    17   -- {* for backward compatibility -- names of variables differ *}
    18   -- {* for backward compatibility -- names of variables differ *}
    18   "(y = None \<Longrightarrow> P) \<Longrightarrow> (\<And>a. y = Some a \<Longrightarrow> P) \<Longrightarrow> P"
    19   "(y = None \<Longrightarrow> P) \<Longrightarrow> (\<And>a. y = Some a \<Longrightarrow> P) \<Longrightarrow> P"