(*setPermBlock with a function*)
  Fixpoint setPermBlockFunc (fp : Z -> option permission) (b : block)
           (ofs : Z) (pmap : access_map) (length: nat): access_map :=
    match length with
      0 => pmap
    | S len =>
      setPerm (fp (ofs + (Z_of_nat len))%Z) b (ofs + (Z_of_nat len))%Z (setPermBlockFunc fp b ofs pmap len)
    end.

Lemma setPermBlockFunc_other_2: forall fp b b' ofs ofs' pmap sz, b <> b' -> (Maps.PMap.get b' (setPermBlock fp b ofs pmap sz)) ofs' = Maps.PMap.get b' pmap ofs'.