aspg-21-1435-1791472391 20261008151311 American Scientific Publishing Group admin@americaspg.com American Scientific Publishing Group International Journal of Neutrosophic Science IJNS 2692-6148 2690-6805 2023 20 1 M. Palanikumar Department of Advanced Mathematical Science, Saveetha School of Engineering, Saveetha University, Saveetha Institute of Medical and Technical Sciences, Chennai-602105, India K. Arulmozhi Department of Mathematics, Bharath Institute of Higher Education and Research, Tamil Nadu, Chennai-600073, India Aiyared Iampan Fuzzy Algebras and Decision-Making Problems Research Unit, Department of Mathematics, School of Science, University of Phayao, Mae Ka, Mueang, Phayao 56000, Thailand Said Broumi Laboratory of Information Processing, Faculty of Science Ben M’Sik, Universit´s Hassan II, BP 7955 Casablanca, Morocco The theory of type-II generalized Pythagorean neutrosophic interval valued soft set (Type-II PyNSIVS) and its application to real problems are introduced in this study. Additionally, we define a few operations using the type-II PyNSIVS set. The Pythagorean neutrosophic interval valued soft (PyNSIVS) set and Pythagorean fuzzy soft set are both generalized to form the type-II PyNSIVS set. Complement, union, intersection, AND, and OR are some examples of operations that we define. In particular, we demonstrate the applicability of De Morgan’s laws, associative laws, and distributive laws in type-II PyNSIVS set. The proposed similarity measure of type-II GPyNSIVS sets serves as the foundation for a strategy we provide for a medical diagnosis challenge. This method of comparing two type-II GPyNSIVS sets can be used to determine if a sick person has a particular disease or not. We support a method using the type-II generalized soft set model to tackle the decision making (DM) problem. We describe the use of a similarity measure between two type-II GPyNSIVS sets in a medical diagnosis situation. To demonstrate how they can be utilized to successfully address issues with uncertainties, illustrative examples are given. 2023 85 105 1435 https://creativecommons.org/licenses/by/4.0/ 10.54216/IJNS.200108 https://www.americaspg.com/journal/21/article/1435 https://www.americaspg.com/storage/71672777761.pdf