Implementing a prioritized logic programming system : thesis

Rule based knowledge representation and reasoning often face a problem of conflict with rules. One common way of solving conflicts is to introduce priorities associate with rules. The thesis describes the underlying algorithm to implement prioritized logic programs (PLPs) proposed by Zhang and Foo in 1997. PLPs are proposed as an extension of Gelfond and Lifschitz's extended logic programs by introducing preferences associatied with rules to the program, where answer sets provide a semantics of PLPs. Major algorithms are presented in detail, and how answer sets can be derived from the algorithm demonstrated. Under this implementation, a PLP is computed efficiently based on previous Niemela and Simons' method of computing stable models of logic programs. Finally, world wide web interface has been employed and embedded to the system to provide great accessibility to the public