intros.
apply split_hd_tl_equality; auto with algebra.
unfold pointwise in |- *; intro; simpl in |- *.
destruct x; (apply Ap_comp; auto with algebra).
Qed.
Hint Resolve pointwise_hd_tl: algebra.

Lemma pointwise_Seqtl :
forall (A B C : Setoid) (n : Nat) (v : seq n A) (w : seq n B)
(op : Map (cart A B) C),
pointwise op (Seqtl v) (Seqtl w) =' Seqtl (pointwise op v w) in seq _ _.