fact: Definition next2s_correct p ps s : (forall i, In i (fst (fst (next2s p ps s))) <-> In i (fst (fst ps)) \/ exists f, In f movel /\ i = f s /\ ~In i (snd (fst ps)) /\ is_odd p) /\ (forall i, In i (snd (fst (next2s p ps s))) <-> In i (snd (fst ps)) \/ exists f, In f movel /\ i = f s /\ ~In i (fst (fst ps)) /\ p <> 1%positive) /\ (forall i, In i (snd (next2s p ps s)) <-> In i (snd ps) \/ exists f, In f movel /\ i = f s /\ ~In i (fst (fst ps)) /\ ~In i (snd (fst ps))).
imports: ZArith List