(*memories that do not contain "dangling pointers"*)
Definition mem_wd m := Mem.inject_neutral (Mem.nextblock m) m.

Lemma mem_wd_inject_splitL: forall j m1 m2
(J:Mem.inject j m1 m2)  (WD: mem_wd m1),
Mem.inject (Mem.flat_inj (Mem.nextblock m1)) m1 m1
/\ j = compose_meminj (Mem.flat_inj (Mem.nextblock m1)) j.