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

(* Specifications: *)
Lemma evalDet_step_done_support_singleton : forall (A : Set)(c : Comp A) s a,
evalDet_step c s = cs_done a s ->
getSupport c = (a :: nil).