New extension principles in fuzzy set theory are proposed. Fuzzy set category by the use of these extension principles is defined. Finally, the rationality of the extension principles is proved. © 1999 Elsevier Science Ltd. All rights reserved.
He, Q., Li, H. X., Chen, C. L. P., & Lee, E. S. (2000). Extension principles and fuzzy set categories. Computers and Mathematics with Applications, 39(1–2), 45–53. https://doi.org/10.1016/s0898-1221(99)00312-0