On Jonsson varieties and quasivarieties


Йонсондық көптүрлiлiк және квазикөптүрлiлiк туралы
О йонсоновских многообразиях и квазимногообразиях
Yeshkeyev A.R.
2021E.A.Buketov Karaganda State University Publish House

Bulletin of the Karaganda University. Mathematics Series
2021#104Issue 4151 - 157 pp.

In this paper, new objects of research are identified, both from the standpoint of model theory and from the standpoint of universal algebra. Particularly, the Jonsson spectra of the Jonsson varieties and the Jonsson quasivarieties are considered. Basic concepts of 3 types of convexity are given: locally convex theory, ϕ(x)-convex theory, J-ϕ(x)-convex theory. Also, the inner and outer worlds of the model of the class of theories are considered. The main result is connected with the question of W. Forrest, which is related to the existential closedness of an algebraically closed variety. This article gives a sufficient condition for a positive answer to this question.

Jonsson quasivariety , Jonsson spectrum , Jonsson theory , Jonsson variety , semantic model

Text of the article Перейти на текст статьи

Karagandy University of the name of academician E.A. Buketov, Karaganda, Kazakhstan

Karagandy University of the name of academician E.A. Buketov

10 лет помогаем публиковать статьи Международный издатель

Книга Публикация научной статьи Волощук 2026 Book Publication of a scientific article 2026