fact: Fixpoint Vfilter A n (l : list (N n)) (v : vector A n) : vector A (length l) := match l as l return vector A (length l) with | nil => Vnil | x :: l' => Vcons (Vnth v x) (Vfilter l' v) end.
imports: CoLoR(VecUtil ListUtil NatUtil LogicUtil ListNodup BoundNat)