The diagnosis frontend of the dlv system

This paper presents the Diagnosis Frontend of dlv, which is a knowledge rep resentation system under development at the Technische Universitat Wien. Th e kernel language of the system is an extension of disjunctive logic progra mming (DLP) by integrity constraints; it offers frontends to several advanc ed knowledge representation formalisms. The formal model of diagnosis emplo yed in the frontend includes both abductive diagnosis (over DLP theories) a nd consistency-based diagnosis. For each of the two diagnosis modalities, g eneric diagnoses, single error diagnoses, and subset minimal diagnoses are considered. We illustrate the use of the frontend by showing the dlv encodi ngs of several diagnosis problems. Thereafter, we discuss implementation is sues. Diagnostic reasoning is implemented on the dlv engine through suitabl e translations of diagnostic problems into disjunctive logic programs, such that their stable models correspond to diagnoses. For the six kinds of dia gnostic reasoning problems emerging from above, such reductions are provide d.