Bayeğ, SelamiMert, Raziye2025-01-062025-01-0620211310-492610.7546/nifs.2021.27.3.9-172-s2.0-85185940676https://doi.org/10.7546/nifs.2021.27.3.9-17https://hdl.handle.net/20.500.14669/1647In this paper, by using ?-and ?-cuts approach and the intuitionistic fuzzy Zadeh’s extension principle, we have proved a result which reveals that the ?-and ?-cuts of an intuitionistic fuzzy number obtained by the intuitionistic fuzzy Zadeh’s extension principle coincide with the images of the ?-and ?-cuts by the crisp function. Then we have given a corollary about monotonicity of the extension principle. Finally, we have extended these results to IFN (?) × IFN (?). © 2021, "Prof. Marin Drinov" Publishing House of Bulgarian Academy of Sciences. All rights reserved.eninfo:eu-repo/semantics/openAccessIntuitionistic fuzzy setsIntuitionistic fuzzy Zadeh’s extension principleZadeh’s extension principleArticle173N/A927