Definition consTailCP {T:Type} {n:nat} (cp : cartesianPower T n) (t : T) : (cartesianPower T (S n)).

Lemma consTlHdHdTl {T:Type} {n:nat} :
forall (A B C : T) (X : cartesianPower T n),
consHeadCP A (consHeadCP B (consTailCP X C)) = consTailCP (consHeadCP A (consHeadCP B X)) C.