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

Lemma exec_skips:
forall {s0 k s k'}
(H1: match_cont (Kseq s0 :: k) (strip_skip' (CC.Kseq s k')))
f ve te m,
match s0 with Sskip => False | Scontinue => False | Sloop _ _ => False
| Sifthenelse _ _ _ => False | Sreturn _ => False
| _ => True end ->
exists k2, strip_skip' (CC.Kseq s k') = CC.Kseq s0 k2 /\
star (CC.State f s k' ve te m) (CC.State f s0 k2 ve te m).