Definition FreelistEffect
m (L: list (Values.block * Z * Z)) (b:Values.block) (ofs:Z): bool :=
List.fold_right (fun X E b z => match X with (bb,lo,hi) =>
E b z || FreeEffect m lo hi bb b z
end)
EmptyEffect L b ofs.

Lemma FreelistEffect_same: forall m bb lo hi mm L
(F:Mem.free m bb lo hi = Some mm)
b (VB: Mem.valid_block mm b) ofs,
FreelistEffect mm L b ofs = false <-> FreelistEffect m L b ofs = false.