Rational Debugging in Logic Programming

A debugger for Prolog has been developed which automates the reasoning ability required to pinpoint errors, resorting to the user only to ask about the intended program semantics, and making cooperative use of the declarative and the operational semantics. The algorithm is expressed in detail, a session protocol exhibited, comparison to other work made, but the implementation is not examined, nor the treatment of Prolog's extra-logical features. This is an abridged version of [Pereira 86].