intuition.
econstructor.
eapply getSupport_NoDup.
apply getSupport_In_evalDist.
Qed.
(* We use evalDist as the probability measure.  Instead of supplying an event on the return type, we expect the computation to test for the occurrence of the event.  *)
Notation "'Pr' [ c  ] " := (evalDist c true) (at level 20).

Lemma evalDist_sum_bind_eq : forall (A B : Set)(eqdb : eq_dec B)(eqda : eq_dec A)(c1 : Comp B)(c2 : B -> Comp A),
sumList (getSupport (Bind c1 c2)) (evalDist (Bind c1 c2)) ==
sumList (getSupport c1) (fun b => evalDist c1 b * (sumList (getSupport (c2 b)) (evalDist (c2 b)))).