Before revision: Namely, each clone C in Post's lattice which contains at least one constant function corresponds to two clones under the less restrictive definition: C, and C together with all nullary functions whose unary versions are in C. If one only considers clones that contain the constant functions, the classification is much simpler: there are only 7 such clones: UM, Λ, V, U, A, M, ⊤.
After revision: andNamely, each clone C in Post's lattice which contains at least one constant function corresponds to two clones under the less restrictive definition: C, and C together with all nullary functions whose unary versions are in C. If one only considers clones that contain the constant functions, the classification is much simpler: there are only 7 such clones: UM, Λ, V, U, A, M, ⊤.