Pixley term

Summary

A Pixley term of a variety is a ternary term $p$ such that $p(x, y, y) = x$, $p(x, x, y) = y$ and $p(x, y, x) = x$ hold. By Pixley's theorem, a variety has a Pixley term if and only if it is an arithmetical variety. A Pixley term is a Mal'cev term that also yields a majority term.