(** Injecting a memory into itself. *)

Definition flat_inj (thr: block) : meminj :=
  fun (b: block) => if plt b thr then Some(b, 0) else None.Definition inject_neutral (thr: block) (m: mem) :=
  mem_inj (flat_inj thr) m m.Remark flat_inj_no_overlap:
  forall thr m, meminj_no_overlap (flat_inj thr) m.

Theorem drop_inject_neutral: forall m b lo hi p m' thr, drop_perm m b lo hi p = Some m' -> inject_neutral thr m -> Plt b thr -> inject_neutral thr m'.