Definition CPToList {T:Type} {n:nat} (cp : cartesianPower T n) : list T.

Lemma nthCircPerm1 {T:Type} {n:nat} :
forall (cp : cartesianPower T (S (S n))) (t Default : T),
t = nthCP 1 cp Default -> t = nthCP (S (S n)) (consTailCP (tailCP cp) (headCP cp)) Default.