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

Lemma setPermBlock_var_other_2: forall p b b' ofs ofs' pmap sz, b <> b' -> (Maps.PMap.get b' (setPermBlock_var p b ofs pmap sz)) ofs' = Maps.PMap.get b' pmap ofs'.