intuition.
rewrite sumList_factor_constant_l.
eapply ratInverse_prod_1.
intuition.
destruct ls; simpl in *.
omega.
eapply sumList_0 in H1.
eapply H.
eauto.
eauto.
simpl.
eauto.
Qed.

Lemma evalDist_lossless : forall (A : Set)(c : Comp A),
well_formed_comp c ->
sumList (getSupport c) (evalDist c) == 1.