Gül Deniz Çaylı | Searcharxiv

arXiv2021

Ordinal sum of two binary operations being a t-norm on bounded lattice

The ordinal sum of t-norms on a bounded lattice has been used to construct other t-norms. However, an ordinal sum of binary operations (not necessarily t-norms) defined on the fixed subintervals of a bounded lattice may not be a t-norm. Some necessary and sufficient conditions are presented in this paper for ensuring that an ordinal sum on a bounded lattice of two binary operations is, in fact, a t-norm. In particular, the results presented here provide an answer to an open problem put forward by Ertuğrul and Yeşilyurt [Ordinal sums of triangular norms on bounded lattices, Inf. Sci., 517 (2020) 198-216].

math.GM↗

arXiv2020

Characterizing idempotent nullnorms on bounded lattices

Nullnorms with a zero element being at any point of a bounded lattice are an important generalization of triangular norms and triangular conorms. This paper obtains an equivalent characterization for the existence of idempotent nullnorms with the zero element $a$ on any bounded lattice containing two distinct elements incomparable with $a$. Furthermore, some basic properties for the bounded lattice containing two distinct element incomparable with a are presented.

math.GM↗