Dipartimento di Matematica Guido Castelnuovo, Sapienza Università di Roma
Radko Mesiar (STU Bratislava)
We discuss and stress the role of ultramodularity in special types of constructions of binary copulas. After recalling of some known ultamodularity-based results, we focus on a the so-called D-product of a copula and its dual. We show that for each copula D which is ultramodular and Schur concave on the left upper triangle of the unit square, this D-product of an arbitrary copula and its dual is again a copula. Several examples and counterexamples are given. Finally, some of our results are generalized to the case of semicopulas and quasi-copulas. Work in collaboration with E. P. Klement, A. Kolesarova and S. Saminger-Platz