(** ** Proof that related states take related steps*)

Lemma find_funct_ptr_ren:
forall (g : genv) b1 b2 ofs (f fg : memren) fn
(Hfg: forall b1 b2, fg b1 = Some b2 -> b1 = b2)
(Hge_wd: ge_wd fg g)
(Hincr: ren_incr fg f)
(Hobs_eq: val_obs f (Vptr b1 ofs) (Vptr b2 ofs))
(Hget: Genv.find_funct_ptr g b1 = Some fn),
b1 = b2.