Connectivity on multi-pretopological structures and decision-making for COVID-19

Abstract Pretopology and multisets have an essential role in mathematics, especially, in some real-life applications. This paper aims to establish a recombination between multisets and pretopology. In addition, some new types of multi-pretopological structures are constructed and some of their properties are investigated. Multi-pre-open sets and multi-pre-closure operator are investigated. Moreover, for the isotonic multi-pretopological structures, and the multi-pre-minimal closed subsets are introduced and studied. Also, the concept of m-pre-connected structures are established as an application of given results and some types of strongly connected structures are investigated. Finally, the effect of multisets in medical information systems has been studied.