University of Sistan and Baluchestan Iranian Journal of Fuzzy Systems 1735-0654 3 2 2006 10 20 Fuzzy sets form A meta-system-theoretic point of view Fuzzy sets form A meta-system-theoretic point of view 1 19 451 10.22111/ijfs.2006.451 EN Amir Daneshgar Amir Hashemi Journal Article 2006 07 20 L-fuzzu sets Enriched category I/O system theory Morphological filtering Translation invariant system https://ijfs.usb.ac.ir/article_451_685c7ee8c6f45c37d1aaa5acd967dfda.pdf