We characterize all functions that can be obtained as a $z$-ordinal sum of semigroups related to continuous t-norms, t-conorms, representable uninorms and idempotent semigroups. We show that this class of functions is bigger than the class of $n$-uninorms with continuous underlying functions. Vice versa, we show that the characterization of $n$-uninorms with continuous underlying functions via $z$-ordinal sum can be extended to any commutative, associative and non-decreasing binary function on the unit interval, which has continuous Archimedean components and is continuous on the diagonal.
Mesiarová-Zemánková, A. (2022). Commutative, associative and non-decreasing functions continuous around diagonal. Iranian Journal of Fuzzy Systems, 19(2), 31-48. doi: 10.22111/ijfs.2022.6786
MLA
A. Mesiarová-Zemánková. "Commutative, associative and non-decreasing functions continuous around diagonal". Iranian Journal of Fuzzy Systems, 19, 2, 2022, 31-48. doi: 10.22111/ijfs.2022.6786
HARVARD
Mesiarová-Zemánková, A. (2022). 'Commutative, associative and non-decreasing functions continuous around diagonal', Iranian Journal of Fuzzy Systems, 19(2), pp. 31-48. doi: 10.22111/ijfs.2022.6786
VANCOUVER
Mesiarová-Zemánková, A. Commutative, associative and non-decreasing functions continuous around diagonal. Iranian Journal of Fuzzy Systems, 2022; 19(2): 31-48. doi: 10.22111/ijfs.2022.6786