8 papers · 1 filter
Higher-dimensional generalized quasiorders
Andrew Moorhead, Reinhard Pöschel
It is well known that the polymorphism clone of a quasiorder is determined by its unary part, in the sense that any operation is a polymorphism if it satisfies the condition that a…
The class of congruence meet semidistributive varieties is not strong Maltsev
Andrew Moorhead
We present a proof that there is no single finite package of identities which characterizes the class of congruence meet semidistributive varieties.
Conservative Maltsev Constraint Satisfaction Problems
Manuel Bodirsky, Andrew Moorhead
One of the central open problems to classify the computational complexity of finite-domain constraint satisfaction problems within P is to prove better algorithmic results for CSPs…
Mal'cev Complexes
Andrew Moorhead
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 sh…
Higher Kiss Terms
Andrew Moorhead
We show that the modular term condition higher commutator is equal to the modular hypercommutator. As a consequence, we arrive at a new proof that HC8 holds for modular varieties.…
Supernilpotent Taylor algebras are nilpotent
Andrew Moorhead
We develop the theory of the higher commutator for Taylor varieties. A new higher commutator operation called the hypercommutator is defined using a type of invariant relation call…