Definition regset_wd rs : Prop :=
      forall r, valid_val f (Pregmap.get r rs).Definition core_wd c : Prop :=
      match c with State rs _ => regset_wd rs end.Definition ge_wd (the_ge: genv) : Prop :=
      (forall b, Maps.PTree.get b (genv_defs the_ge) ->
            f b) /\
      (forall id ofs v, Senv.symbol_address the_ge id ofs = v ->
                   valid_val f v).

Lemma valid_symb: forall f fg g id i (Hge_wd: ge_wd fg g) (Hincr: ren_domain_incr fg f), valid_val f (symbol_address g id i).