Yeshkeyev, A.R.; Yarullina, A.R.; Amanbekov, S.M.
(Bulletin of the Karaganda University. Mathematics series, 2023)
The article is devoted to the study of semantic Jonsson quasivarieties of universal unars and undirected graphs. The first section of the article consists of basic necessary concepts from Jonsson model theory. The following ...