induction 1; intuition; subst.
discriminate.
inversion H1; clear H1; subst.
inversion H0; clear H0; subst.
econstructor. econstructor.
intuition.
destruct (IHevalDet_steps c s); eauto.
destruct H0; intuition.
exists x.
exists x0.
intuition.
econstructor.
rewrite <- H.
eauto.
rewrite <- H.
trivial.
Qed.

Lemma evalDet_steps_eof_inv : forall (A : Set)(c : Comp A) s,
evalDet_steps (cs_more c s) (@cs_eof A) ->
exists c'' s'', evalDet_steps (cs_more c s) (cs_more c'' s'') /\ evalDet_step c'' s'' = (@cs_eof A).