Mal'cev Complexes

Abstract

It is well known that an equivalence relation is invariant under the basic operations of an algebra if and only if it is invariant under the unary polynomials of the algebra. We show that a higher arity version of this property holds for a higher dimensional analogue of an equivalence relation. It follows that the hypercommutator of arity $n$ for an algebra is determined by its $n$-ary polynomials. We construct examples to show that this fails for every arity of the term condition higher commutator.