The idea of ambiguous set (AS) theory has been introduced to describe the uncertainties, imprecisions and haziness innate in information. This study generalizes the notion of AS to a single-valued ambiguous number (SVAN). We propose the concepts of partial ambiguous order set (PAOS) and lattice...

We provide a new characterization of binary relations that have an open graph. This result is applicable to any binary relation on any topological space. The relationship of this new theorem to several known results for binary relations used for preference representation, namely strict partial...

In this paper, we show that the correspondence discovered by Koshevoy ([18]) and Johnson and Dean ([15],[16]) between anti-exchange closure operators and path independent choice operators is a duality between two semilattices of such operators. Then we use this duality to obtain results...