4 citations · 20 across the 12 of their papers we have counts for
12 papers
The Agda Universal Algebra Library, Part 1: Foundation
William DeMeo
The Agda Universal Algebra Library (UALib) is a library of types and programs (theorems and proofs) we developed to formalize the foundations of universal algebra in dependent type…
The Agda Universal Algebra Library, Part 2: Structure
William DeMeo
The Agda Universal Algebra Library (UALib) is a library of types and programs (theorems and proofs) we developed to formalize the foundations of universal algebra in dependent type…
Polynomial-time Tests for Difference Terms in Idempotent Varieties
William DeMeo, Ralph Freese, Matthew Valeriote
We consider the following practical question: given a finite algebra A in a finite language, can we efficiently decide whether the variety generated by A has a difference term? We…
Constraint Satisfaction Problems over Finite Structures
Libor Barto, William DeMeo, Antoine Mottet
We initiate a systematic study of the computational complexity of the Constraint Satisfaction Problem (CSP) over finite structures that may contain both relations and operations. W…
Bounded homomorphisms and finitely generated fiber products of lattices
William DeMeo, Peter Mayr, Nik Ruskuc
We investigate when fiber products of lattices are finitely generated and obtain a new characterization of bounded lattice homomorphisms onto lattices satisfying a property we call…
The Commutator as Least Fixed Point of a Closure Operator
William DeMeo
We present a description of the (non-modular) commutator, inspired by that of Kearnes in~\cite[p.~930]{MR1358491}, that provides a simple recipe for computing the commutator.
Universal Algebraic Methods for Constraint Satisfaction Problems
Clifford Bergman, William DeMeo
After substantial progress over the last 15 years, the "algebraic CSP-dichotomy conjecture" reduces to the following: every local constraint satisfaction problem (CSP) associated w…
Isotopic algebras with non-isomorphic congruence lattices
William DeMeo
We give examples of pairs of isotopic algebras with non-isomorphic congruence lattices. This answers the question of whether all isotopic algebras have isomorphic congruence lattic…
Dedekind's Transposition Principle for lattices of equivalence relations
William DeMeo
We prove a version of Dedekind's Transposition Principle that holds in lattices of equivalence relations.
Congruence lattices of finite algebras
William J. DeMeo
An important and long-standing open problem in universal algebra asks whether every finite lattice is isomorphic to the congruence lattice of a finite algebra. Until this problem i…
Interval enforceable properties of finite groups
William DeMeo
We propose a classification of group properties according to whether they can be deduced from the assumption that a group's subgroup lattice contains an interval isomorphic to some…
Expansions of finite algebras and their congruence lattices
William DeMeo
We present a novel approach to the construction of new finite algebras and describe the congruence lattices of these algebras. Given a finite algebra , let $B_1, B_2,…