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

Lemma continue_cont_is:
forall k, match (continue_cont k) with nil => True | Kseq e3 :: Kloop2 s e3' :: _ => e3=e3' | _ => False end.