Inductive plus: state -> state -> Prop :=
  | plus_left: forall s1 s2 s3,
      CCstep s1 s2 -> star s2 s3 -> plus s1 s3.Inductive plus: state -> state -> Prop :=
  | plus_left: forall s1 s2 s3,
      CCstep s1 s2 -> star s2 s3 -> plus s1 s3.

Lemma strip_skip'_call: forall f ve te m lid f' ve' te' k1 k, CC.Kcall lid f' ve' te' k1 = strip_skip' k -> star (CC.State f Sskip k ve te m) (CC.State f Sskip (CC.Kcall lid f' ve' te' k1) ve te m).