These are some of the projects that I'm working on.

1. Learning and its role in reasoning. Specifically, I'm interested in provably correct learning methods to make reasoning more efficient.
2. Planning and learning (with my PhD student Ricky Lau). We are using Planner-R to experiment how learning can help planning. This is an ongoing RGC CERG project.
3. ASSAT - computing answer sets by using SAT solvers (with my PhD student Yuting Zhao). By adding so-called loop formulas to program completions, we showed that answer sets of a logic programs can be computed using SAT solvers such as Chaff2. Our experimental results so far have shown that computing answer sets this way has advantages over specialized answer set generators. Here is a paper that reports some preliminary results, and here is the home page for our ASSAT system.
4. Abduction in logic programming (with Prof. Jia-Huai You of University of Alberta). Here is our IJCAI-01 paper about this work. An expanded version of this paper is to appear in Artificial Intelligence.
5. Strongest necessary conditions, weakest sufficient conditions, and their applications. Given a proposition, if you want to find out what is the minimal assumption that you must make in order for this proposition to be true, then what you need is exactly the weakest sufficient condition of this proposition. If you want to see how much you can conclude once you add this proposition to your knowledge base, then you are looking the strongest necessary condition of this proposition. Here is my paper at KR2000 about these two conditions in propositional case. An  expanded version of this paper appeared in Artificial Intelligence 128 (1-2) (2001) pp. 143-159.
6. Formalizing control information in the situation calculus.
7. Causal action theories.

Created by Fangzhen Lin on Feb-23-2002.