Clocked Temporal Logic Programming

This dissertation discusses an extension of temporal logic with granularity of time and develops a temporal logic programming language Chronolog(MC) as a new member of the Chronolog family of languages based on the logic. The rst contribution of the thesis is to develop a temporal logic, called TLC (Temporal Logic with Clocks), in which each predicate symbol, and hence each formula, is associated with a local clock. Due to the introduction of local clocks to formulae, TLC is more powerful and more exible in many applications, such as the representation of local properties of processes in a reactive/concurrent system, expressing temporal relations in a database and making temporal queries to a given temporal database, and knowledgebased simulation. The second contribution of the thesis is to develop a temporal logic programming language, called Chronolog(MC) (Chronolog with Multiple Clocks). Chronolog(MC) is based on an executable subset of TLC, just as Prolog is based on an executable subset of rst-order logic. In Chronolog(MC), each predicate symbol appearing in the program body is assigned a local clock through a clock de nition and assignment. Chronolog(MC) can be used in applications where the notion of dynamic change is central. The third contribution of the thesis is to provide several problem-oriented techniques for the application of TLC and Chronolog(MC), including a knowledge speci cation methodology for solving simulation problems, and a temporal reasoning methodology for reactive and concurrent systems. We also propose an approach to embed a timing system into the logic TLC such that it can e ectively be used for specifying and reasoning about the behavior of those systems, where granularity of time is needed. vii