intuition.
subst.
eapply list_pred_eq.
Qed.

Lemma compMap_support :
forall (A B : Set)(P : A -> B -> Prop)(eqd : EqDec B)(c : A -> Comp B)(lsa : list A)(lsb : list B),
In lsb (getSupport (compMap _ c lsa)) ->
(forall a b, In a lsa -> In b (getSupport (c a)) -> P a b) ->
list_pred P lsa lsb.