Problem:
 Ap(Ap(Ap(S(),x),y),z) -> Ap(Ap(x,z),Ap(y,z))
 Ap(Ap(K(),x),y) -> x
 Ap(I(),x) -> x
 Ap(D0(),Ap(Ap(D(),z0),z1)) -> z0
 Ap(D1(),Ap(Ap(D(),z0),z1)) -> z1
 Ap(Ap(D(),Ap(D0(),z)),Ap(D1(),z)) -> z

Proof:
 Open