Connectivity with respect to α-discrete closure operators

Abstract

We discuss certain closure operators that generalize the Alexandroff topologies. Such a closure operator is defined for every ordinal α>0\alpha \gt 0 in such a way that the closure of a set AA is given by closures of certain α\alpha -indexed sequences formed by points of AA. It is shown that connectivity with respect to such a closure operator can be viewed as a special type of path connectivity. This makes it possible to apply the operators in solving problems based on employing a convenient connectivity such as problems of digital image processing. One such application is presented providing a digital analogue of the Jordan curve theorem.

Keywords

• closure operator
• ordinal (number)
• ordinal-indexed sequence
• connectivity
• digital jordan curve
• 54a05
• 54d05