Abstract Diagnosis of First Order Functional Logic Programs

Abstract. We present a generic scheme for the abstract debugging of functional logic programs. We associate to programs a semantics based on a (continuous) immediate consequence operator, P R, which mod-els correctly the powerful features of modern functional logic languages (non-deterministic, non-strict functions defined by non-confluent pro-grams and call-time choice behaviour). Then, we develop an effective debugging methodology which is based on abstract interpretation: by approximating the intended specification of the semantics of R we de-rive a finitely terminating bottom-up diagnosis method, which can be used statically. Our debugging framework does not require the user to provide error symptoms in advance and is applicable with partial speci-fications and even partial programs.