Distinguishable Entities: Definitions and Properties

Many studies in natural language processing are concerned with how to generate definite descriptions that evoke a discourse entity already introduced in the context. A solution to this problem has been initially proposed by Dale (1989) in terms of distinguishing descriptions and distinguishable entities. In this paper, we give a formal definition of the terms "distinguishable entity" in non trivial cases and we show that its properties lead us to the definition of a distance between entities. Then, we give a polynomial algorithm to compute distinguishing descriptions.