Definition CMin_halted (q : CMin_core): option val :=
match q with
CMin_Returnstate v Kstop => Some v
| _ => None
end.

(* Specifications: *)
Lemma CMin_corestep_not_halted : forall ge m q m' q',
CMin_corestep ge q m q' m' -> CMin_halted q = None.
Lemma CMin_at_external_halted_excl :
forall q, CMin_at_external q = None \/ CMin_halted q = None.