Pythagorean Fuzzy Full Implication Triple I Method and Its Application in Medical Diagnosis

This paper is devoted to the research of full implication triple I method under Pythagorean fuzzy environment. We first propose concepts t-norm, t-conorm, residual operator (RPFIO) and biresiduum. The for modus ponens (PFMP) tollens (PFMT) are also established. In addition, properties PFMP PFMT models including robustness, continuity reversibility analyzed. Finally, a practical problem discussed demonstrate effectiveness multiple in medical diagnosis. advantages new explained. Overall, compared with existing methods, proposed methods based on logical reasoning rather than using aggregation operators, so they can more accurately completely express decision information.