The problem of determining the equivalence of knowledge descriptions (logical theories, ontologies, programs, databases, and so on) is an important one, not only in core knowledge representation and reasoning topics, but also in many everyday issues such as data integration. This paper focuses on analyzing problems of equivalence and synonymy in answer set programming (ASP), and relating different conceptual schemes within this fixed framework. The authors first propose a set of desiderata for developing a concept of synonymy, and then discuss the definition of a strong concept of equivalence for theories in quantified equilibrium logic (which is used in a standard way to interpret ASP). They then provide different characterizations and show that they satisfy the desiderata. A salient aspect of this work is that the authors provide a valuable detailed case study that illustrates the application of these concepts in real-world scenarios.

In conclusion, this paper will be of interest to researchers in areas of knowledge representation and reasoning, but it should also find application in many practical venues. For instance, reasoning with and making sense of heterogeneous pieces of information obtained from the web is a central problem for today’s information systems, and determining equivalence is a key aspect of this task.