src/HOL/Fun.thy
changeset 44860 56101fa00193
parent 44744 bdf8eb8f126b
child 44890 22f665a2e91c
equal deleted inserted replaced
44859:237ba63d6041 44860:56101fa00193
     4 *)
     4 *)
     5 
     5 
     6 header {* Notions about functions *}
     6 header {* Notions about functions *}
     7 
     7 
     8 theory Fun
     8 theory Fun
     9 imports Complete_Lattice
     9 imports Complete_Lattices
    10 uses ("Tools/enriched_type.ML")
    10 uses ("Tools/enriched_type.ML")
    11 begin
    11 begin
    12 
    12 
    13 lemma apply_inverse:
    13 lemma apply_inverse:
    14   "f x = u \<Longrightarrow> (\<And>x. P x \<Longrightarrow> g (f x) = x) \<Longrightarrow> P x \<Longrightarrow> x = g u"
    14   "f x = u \<Longrightarrow> (\<And>x. P x \<Longrightarrow> g (f x) = x) \<Longrightarrow> P x \<Longrightarrow> x = g u"