Report on the 17th International RCRA Workshop (RCRA 2010)

Marco Gavanelli, University of Ferrara, Italy
Toni Mancini, Sapienza university of Rome, Italy

Logic programming had always to face the hard truth that many problems it addresses have a combinatorial nature, for which no polynomial algorithm has been proposed notwithstanding decades of research.

Nonetheless, the logic programming community is not alone in its search for algorithms that are efficient in practice, as many communities tend to address same problems from different perspectives: in Constraint Programming the focus is often on global constraints, while in OR it is on computing tight relaxations and in SAT it is on intelligent backtracking algorithms. Logic Programming spawned Constraint Logic Programming and Answer Set Programming, that address often the very same problems.

Although years ago all these communities were almost disjoint, nowadays there is more and more interest in joining the efforts, an approach that often leads to success stories, as witnessed, for example, by Cmodels (an ASP solver based on SAT solving), or by the recent success of the ASP solver CLASP in SAT competitions.

The RCRA workshop has the ambitious goal to be a sort of Rosetta Stone and have these communities dialogue and exchange ideas, despite the different languages they talk and the different backgrounds, to get faster solving algorithms. The last editions have been on the experimental evaluation of algorithms for problems with combinatorial explosion.

RCRA 2010 was held in Bologna, in association with CP-AI-OR, the international conference on the integration of Artificial Intelligence and Operations Research in Constraint Programming. Of the 17 presented papers, 7 were on Logic Programming, and the authors had the opportunity to show the efficiency of their systems, and to spread the declarative programming word, to researchers coming from different communities (like planning or natural language processing) used to address problems with local search, greedy algorithms or Lagrangean relaxation.

A selection of the best papers of RCRA 2010 will be published on a special issue of the Annals of Mathematics and Artificial Intelligence, currently under review.

The workshop is organised by the RCRA interest group of the Italian Association for Artificial Intelligence (AI*IA) focussing on knowledge representation and automated reasoning. The group organises its annual meetings since 1994.