PROGRAMMING IN LOGIC WITHOUT LOGIC PROGRAMMING

Logic programs. production systems, BDI agent systems, active databases and many other languages express programs by means of rules of the form if antecedent then consequent. However, despite the seemingly logical character of these rules, only logic programming and MetaTem give such rules a logical interpretation. In this talk, I will argue that the MetaTem interpretation is more fundamental than the logic programming interpretation, but that MetaTem is limited by its use of modal temporal logic for representing change of state and of frame axioms for generating state transitions.

                  As a practical alternative to MetaTem, I will propose a logic-based language in which rules are represented in classical, non-modal logic with explicit time, state transitions are performed by destructive updates, and (as in MetaTem) computation is the task of generating a model that makes all of the rules true.  I will illustrate the language with examples of programs that have the form if a complex event occurs then a complex transaction (or plan of actions) is performed. I will also argue that logic programming has a useful (but only subordinate) role to play in the language.