Definition PMap_eq {A} (m m' : PMap.t (Z -> A)) := forall b' ofs', m !! b' ofs' = m' !! b' ofs'.

Lemma A2PMap_found A m b ofs ofs' o :
AMap.find (elt:=A) (b, ofs) m = Some o ->
(ofs <= ofs' < ofs + LKSIZE)%Z ->
(A2PMap m) !! b ofs' = Some Writable.