Definition freshloc m m' b := andb (valid_block_dec m' b) (negb (valid_block_dec m b)).

Lemma freshloc_trans: forall m m'' m' b
(FWD: mem_forward m m'') (FWD': mem_forward m'' m'),
(orb (freshloc m m'' b) (freshloc m'' m' b)) = freshloc m m' b.