Existentially Definable Factor Congruences
Logic
2010-11-16 v1
Abstract
A variety V has definable factor congruences if and only if factor congruences can be defined by a first-order formula Phi having central elements as parameters. We prove that if Phi can be chosen to be existential, factor congruences in every algebra of V are compact.
Keywords
Cite
@article{arxiv.0906.4722,
title = {Existentially Definable Factor Congruences},
author = {Pedro Sánchez Terraf},
journal= {arXiv preprint arXiv:0906.4722},
year = {2010}
}