Classification and construction of picture fuzzy topological spaces

This paper initiates the study of picture fuzzy topological spaces. In order to develop a mechanism to construct picture fuzzy topological spaces, we prove some basic results related to picture fuzzy sets together with the introduction of many new notions such as balanced and \r{ho}-equivalent relations on picture fuzzy sets. We also define the rank, picture fuzzy base and picture fuzzy sub-base of picture fuzzy topological spaces. With the help of these notions, we present a method to design picture fuzzy topological spaces, which is the main outcome of this work. To the best of our knowledge, this is the first serious attempt to study picture fuzzy topological spaces. It is hoped that, this study will provide a decent platform for further development of picture fuzzy topological spaces and their applications in decision making theory.