(*LENB: Cminor.v requires v to be Vint i -should we keep this condition?*)
Definition CMin_halted (q : CMin_core): option val :=
    match q with
       CMin_Returnstate v Kstop => Some v
     | _ => None
    end.

Lemma CMin_at_external_halted_excl : forall q, CMin_at_external q = None \/ CMin_halted q = None.