Definition CMinSel_halted (q : CMinSel_core): option val :=
    match q with
       CMinSel_Returnstate v Kstop => Some v
     | _ => None
    end.

Lemma CMinSel_corestep_not_halted : forall ge m q m' q', CMinSel_corestep ge q m q' m' -> CMinSel_halted q = None.