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_comm b1 o1 b2 o2 e: PMap_eq (setPerm (Some Writable) b1 o1 (setPerm (Some Writable) b2 o2 e)) (setPerm (Some Writable) b2 o2 (setPerm (Some Writable) b1 o1 e)).