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_Dtrue: forall m bb lo hi L b ofs
(F:FreelistEffect m ((bb, lo, hi) :: L) b ofs = true),
FreelistEffect m L b ofs = true \/
FreeEffect m lo hi bb b ofs = true.