Majority term

Summary

A majority term is a ternary term $m(x, y, z)$ that returns the value shared by at least two of its three arguments. It is the near-unanimity term of the smallest possible arity. Lattices and Boolean algebras have a majority term, and every variety with a majority term is congruence-distributive. For a finite algebra with a majority term, the term operations are exactly the operations that preserve the subalgebras of its square.