Applications of Preferences using Answer Set Programming

Preferences are useful when the space of feasible solutions of a given problem is dense but not all these solutions are equivalent w.r.t. some additional requirements. In this case, the goal is to find feasible solutions that most satisfy these additional requirements. In order to represent preferences, in this paper we use an extension of ordered disjunction programs. Ordered disjunction is an approach based on answer sets that allows us to represent alternative, ranked options for a problem. Moreover, we give a brief overview of two real applications of extended ordered programs in two different domains. The first one is in planning: evacuation planning. The second one is in argumentation: organ transplantation. In particular, we show the role of negated negative literals in extended ordered programs to obtain the preferred solution of each application.