Öner, T.Katican, T.Borumand Saeid, A.B.2025-12-302025-12-3020251224-17841844-0835https://doi.org/10.2478/auom-2025-0030https://hdl.handle.net/20.500.14365/8456In this study, Sheffer stroke Nelson algebras (briefly, s-Nelson algebras), (ultra) ideals, quasi-subalgebras, quotient sets, and fuzzy structures on these algebraic structures are introduced. The relationships between s-Nelson and Nelson algebras are analyzed. It is also shown that an s-Nelson algebra is a bounded distributive modular lattice, and the family of all ideals forms a complete distributive modular lattice. A congruence relation on an s-Nelson algebra is determined by an ideal and quotient s-Nelson algebras are constructed by this congruence relation. Finally, it is indicated that a quotient s-Nelson algebra constructed by the ultra ideal is totally ordered and that the cardinality of the quotient is less than or equal to 2. © 2025 Tahsin Oner et al., published by Ovidius University of Constanta.eninfo:eu-repo/semantics/openAccess(Ultra) IdealNelson AlgebraPrimary 06F05, 03G25Quasi-SubalgebraS-Nelson AlgebraSecondary 03G25, 03G10Sheffer StrokeArticle10.2478/auom-2025-00302-s2.0-105026065258