Soft Intersection Quasi-interior Ideals of Semigroups

It has been shown that generalizing the ideals of an algebraic structure is both interesting and beneficial for mathematicians. In this context, the concept of quasi-interior (Ԛꟾ) ideal was introduced as a generalization of quasi-ideal and interior ideal of a semigroup. In this paper, we apply this concept to soft set theory and semigroups, introducing a new form of soft intersection (S-int) ideal called the "soft intersection (S-int) quasi-interior (Ԛꟾ) ideal." The main objective of this study is to investigate the relationships between S-int Ԛꟾ ideals and other specific types of S-int ideals in a semigroup. It has been shown that every S-int interior ideal of a semigroup is an S-int Ԛꟾ ideal, and every S-int ideal is an S-int Ԛꟾ ideal. The S-int bi-ideal of a group is an S-int Ԛꟾ ideal, the S-int quasi-ideal of a regular group is an S-int Ԛꟾ ideal, the idempotent S-int Ԛꟾ ideal is an S-int bi-quasi-ideal and an S-int bi-interior ideal. Counterexamples are provided to show that the opposites of these statements are not always valid. We prove that for the converses to hold, the semigroup should be a group or regular, or the S-int Ԛꟾ ideal should be idempotent. Our main theorem, which demonstrates that if a subsemigroup of a semigroup is a Ԛꟾ ideal, then its soft characteristic function is an S-int Ԛꟾ ideal, and vice versa, enables us to establish a connection between semigroup theory and soft set theory. Through this theorem, we illustrate how this concept connects to the existing algebraic structures in classical semigroup theory. Additionally, we offer conceptual characterizations and an analysis of the concept in terms of soft set operations, including soft image and soft inverse image, supporting our claims with specific, informative examples. Furthermore, the connection between a regular semigroup and the structure of S-int Ԛꟾ ideals is established and presented.