Enhancing the Power and Performance of Tabled Evaluation of Logic Programs

该项目继续进行XSB系统的开发工作。 XSB是一个集逻辑程序设计、演绎数据库和非单调推理于一体的系统。它采用表式求值策略SLG分解，将联合收割机Prolog的SLD和演绎数据库的自底向上求值以计算有效的方式结合起来。目前的基准测试表明，XSB系统是显着快于传统的方法来演绎数据库查询评估，并显示出非常有效的某些类型的非单调推理的承诺。 在当前的项目中，XSB的实现将通过以下方式得到改进：（1）改进底层的基于WAM的引擎，使其更有效;（2）开发程序转换技术，使XSB程序能够在源代码级别进行优化。

This project continues work on the development of XSB system. XSB is a system that integrates logic programming, deductive databases and nonmonotonic reasoning. It uses SLG resolution, a tabled evaluation strategy, to combine Prolog's SLD and deductive databases's bottom up evaluation in a computationally effective way. Current benchmarks show that the XSB system is significantly faster than more traditional approaches to deductive database query evaluation, and shows promise of being very efficient for certain types of nonmonotonic reasoning. In the current project, the XSB implementation will be improved by; (1) improving the underlying WAM-based engine to make it more efficient, and (2) developing program transformation techniques to permit XSB programs to be optimized at the source level.