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

Lemma evalDet_step_more_nil_inv : forall (A : Set)(c c' : Comp A) ls,
evalDet_step c nil = (cs_more c' ls) ->
ls = nil.