Definition A2P {A} :=
 (fun (pmap : access_map) (a : address * A) =>
      let (a0, _) := a in let (b0, ofs0) := a0 in setPermBlock (Some Writable) b0 ofs0 pmap LKSIZE_nat).

Lemma setPerm_congr b o e e': PMap_eq e e' -> PMap_eq (setPerm (Some Writable) b o e) (setPerm (Some Writable) b o e').