intuition.
simpl.
eapply leRat_trans.
eapply sumList_le; intuition.
eapply ratMult_leRat_compat.
eapply leRat_refl.
eapply H0.
trivial.
rewrite sumList_factor_constant_r.
rewrite evalDist_lossless.
rewrite ratMult_1_l.
intuition.
trivial.
Qed.

Lemma evalDist_ret_1 :
forall (A : Set)(eqd : eq_dec A)(a1 a2 : A),
a1 = a2 ->
evalDist (Ret eqd a1) a2 = 1.