Extended Query Facilities for Racer and an Application to Software-Engineering Problems

er reports on a pragmatic query language for Racer. The abstract syntax and semantics of this query language is defined. Next, the practical relevance of this query language is shown, applying the query answering algorithms to the problem of consistency maintenance between object-oriented design models. 1 Motivation Practical description logic (DL) systems such as Racer [3] offer a functional API for querying a knowledge base (i.e., a tuple of T-box and A-box). For instance, Racer provides a query function for retrieving all individuals mentioned in an Abox that are instances of a given query concept. Let us consider the following Abox: {has child(alice, betty), has child(alice, charles)}. If we are interested in finding individuals for which it can be proven that a child exists, in the Racer system, the function concept instances can be used. However, if we would like to find all tuples of individuals x and y such that a common parent exists, currently, it is not possible to express ...

• Type: Conference
• Year: 2004
• Where: DLOG
• Authors: Volker Haarslev, Ralf Möller, Ragnhild Van Der Straeten, Michael Wessel
• Keywords: Automated Reasoning, DLOG 2004, Pragmatic Query Language, Query Answering Algorithms, Query Language