arXiv:1008.3879v1 [cs.AI] 23 Aug 2010

# A Formalism For Causal Explanations With An Answer Set Programming Translation

HAL version, Aug 23, 2010 see LNCS (KSEM 2010) for conference **version.**
Yves Moinard INRIA Bretagne Atlantique, IRISA, Campus de Beaulieu, 35042 Rennes cedex, France email: moinard@irisa.fr July 18, 2020

## Abstract 1

We examine the practicality for a user of using Answer Set Programming (ASP) for representing logical formalisms. Our example is a formalism aiming at capturing causal explanations from causal information. We show the naturalness and relative efficiency of this translation job. We are interested in the ease for writing an ASP program. Limitations of the earlier systems made that in practice, the "declarative aspect" was more theoretical than practical. We show how recent improvements in working ASP systems facilitate the translation.

## 1 Introduction

We consider a formalism designed in collaboration with Philippe Besnard and Marie-Odile Cordier, aiming at a logical formalization of explanations from causal and "is-a" statements. Given some information such as "fire causes smoke" and "grey smoke is a smoke", if "grey smoke" is established, **we want to**
infer that "fire" is a (tentative) explanation for this fact. The formalization [2] is expressed in terms of rules such as "if α causes β and γ isa β, then **α explains γ** provided {α, γ} is possible**". This concerns looking for paths in a graph and**
ASP is good for this. There exists efficient systems, such as DLV [6] or clasp[D] (www.dbai.tuwien.ac.at/proj/dlv/ or potassco.sourceforge.net/).

Transforming formal rules into an ASP program is easy. ASP should then be an interesting tool for researchers when designing a new theoretical formalization as the one examined here. When defining a theory, ASP programs should help examining a great number of middle sized examples. Then if middle sized programs could work, a few more optimization techniques could make **real sized** examples work with the final theory.

In fact, even if ASP allows such direct and efficient translation, a few **problems complicate the task. The poor data types available in pure ASP systems is**