Title: Characterizations of idempotent discrete uninorms,
Abstract: In this paper we provide an axiomatic characterization of the idempotent
discrete uninorms by means of three conditions only: conservativeness,
symmetry, and nondecreasing monotonicity. We also provide an alternative
characterization involving the bisymmetry property. Finally, we provide a
graphical characterization of these operations in terms of their contour plots,
and we mention a few open questions for further research.