Facets of congruence distributivity in Goursat categories

JOURNAL OF PURE AND APPLIED ALGEBRA

卷:224

Article

Gran, Marino¹  Rodelo, Diana^2,3  Nguefeu, Idriss Tchoffo¹ 

[1] Catholic Univ Louvain, Inst Rech Math & Phys, Chemin Cyclotron 2, Louvain La Neuve 1348, Belgium

[2] Univ Algarve, Fac Ciencias & Tecnol, Dept Matemat, Campus Gambelas, P-8005139 Faro, Portugal

[3] Univ Coimbra, Dept Math, CMUC, P-3001501 Coimbra, Portugal

关键词: Mal'tsev categories;    Goursat categories;    Congruence distributive varieties;    Shifting Lemma;    Triangular Lemma;    Trapezoid Lemma;   

DOI  :  10.1016/j.jpaa.2020.106380

来源: Elsevier

【 摘 要 】

We give new characterisations of regular Mal'tsev categories with distributive lattice of equivalence relations through variations of the so-called Triangular Lemma and Trapezoid Lemma in universal algebra. We then give new characterisations of equivalence distributive Goursat categories (which extend 3-permutable varieties) through variations of the Triangular and Trapezoid Lemmas involving reflexive and positive relations. (C) 2020 Elsevier B.V. All rights reserved.

【 授权许可】

Free