On δ-Sequential Spaces

Sequence converges is an important research object in topology and analysis, since it closely related to continuity, compactness other properties. In this article, we use the notion of regularly convergence, which a generalization convergence notion, define sequentially closed sets operator sequential closure; then consider thier charactarizations prove that are coincide regular spaces. Finally introduce new axioms by involving δ-open open with concept convergence; namely δ-sequential space r-sequential space, when show there no general relations between these spaces addition some statements as; r-first countable δ-sequential, stronger than both compact r-T_2