proposition: Lemma consTailCPTl {T:Type} {n:nat} : forall (cp : cartesianPower T (S (S n))) t, tailCP (consTailCP cp t) = consTailCP (tailCP cp) t.
proof: Proof. intro cp; induction n; simpl; reflexivity. Qed.
imports: Arith NArith List Sorting Coq.Program.Equality