induction c; intuition; simpl in *.
inversion H; clear H; subst.
trivial.
case_eq (evalDet_step c s); intuition;
rewrite H1 in H0; try discriminate.
case_eq (shiftOut s n); intuition;
rewrite H0 in H.
destruct p.
inversion H; clear H; subst.
discriminate.
discriminate.
Qed.

Lemma evalDet_step_app_more_eq : forall (A : Set)(c c': Comp A) s s' s'',
evalDet_step c s = (cs_more c' s'') ->
evalDet_step c (s ++ s') = (cs_more c' (s'' ++ s')).