Miguel Cruz Costa Calejo A Framework

This thesis describes a new approach to declarative debugging (error diagnosis) of logic programs. The main contributions are: • “Declarative source debugging”, a new approach requiring less queries from the user. • Improved algorithms for classical “declarative execution debugging”. • Support for Prolog impurities, such as cuts and side-effects. • The use of suspect trees, allowing uniform treatment of all considered bug types. • More extensive use of the available user knowledge. • An approach for debugging meta-interpreted and pre-processed programs. • An implementation architecture designed for large program computations, but not tested on large programs. • An experimental prototype incorporating these improvements. • An application of the debugging framework to the problem of knowledge base updating. The concepts and methods are layered according to the programming language: from pure Horn logic (normal) programs to full Prolog.