Section FixM.
Variable M : SBTM.
Notation END := 0.
Notation X := 1.
Notation "⦇" := 2.
Notation "⦈" := 3.
Notation tt := 4.
Notation ff := 5.
Notation "!! b" := (if b then tt else ff) (at level 1).
Notation "! p" := (@enc_state M p) (at level 1).

Lemma rev_sim_swap t q z :
SR.rew (map SR.swap (R M)) (enc_conf M t q) z -> exists q' t' w m, trans M (q', curr t') = Some (q, w, m) /\ t = mv m (wr w t') /\ z = enc_conf M t' q'.