(** Memory states that inject into themselves. *)
Definition flat_inj (thr: block) : meminj :=
fun (b: block) => if plt b thr then Some(b, 0) else None.
Parameter inject_neutral: forall (thr: block) (m: mem), Prop.

Axiom neutral_inject:
forall m, inject_neutral (nextblock m) m ->
inject (flat_inj (nextblock m)) m m.