The similarity of closures of Jonsson sets

This article is devoted to the study model-theoretic properties of special closures of Jonsson sets. That is considered a syntactic similarity of Jonsson theories for universal existential sentences which true in these models. Due to the fact that the fragments of Jonsson sets are Jonsson theories, such an approach for the study of such theories is acceptable. Besides define the certain range of questions not previously are risen in studies such theories and its of their models classes.