Plithogenic Fuzzy Natural Language and Its Upside-Down Logic: A Framework for Contradiction-Aware Reasoning

In the real world, many reversal phenomena occur, such as cases where a statement once regarded as false is later recognized as true. Upside-Down Logic is a framework designed to formalize such reversal phenomena as a logical system. It inverts the truth and falsity of lemmas through contextual transformations, thereby capturing ambiguity and reversals within reasoning processes. A Plithogenic Set models elements by means of attribute-based membership and contradiction functions, extending the classical frameworks of fuzzy, intuitionistic, and neutrosophic sets. In this paper, we investigate Plithogenic Fuzzy Natural Language, a concept that augments Fuzzy Natural Language by incorporating the notion of contradiction.