Definition local_out_of_reach mu (m : mem) (b : block) (ofs : Z): Prop :=
  locBlocksTgt mu b = true /\
  forall b0 delta, local_of mu b0 = Some (b, delta) ->
                  (~ Mem.perm m b0 (ofs - delta) Max Nonempty \/
                   pubBlocksSrc mu b0 = false).

Lemma genv2blocksBool_char2': forall F V (ge : Genv.t F V) b, (snd (genv2blocksBool ge)) b = false <-> ~ snd (genv2blocks ge) b.