Definition smvalid_tgt (mu : SM_Injection) m2 :=
forall b2, RNG mu b2 -> Memory.Mem.valid_block m2 b2.

Lemma extern_incr_as_inj: forall mu mu'
(INC: extern_incr mu mu') (WD': SM_wd mu'),
inject_incr (as_inj mu) (as_inj mu').