An ET-Based Low-Level Solution for Query-Answering Problems

Query-answering QA problems have attracted wider attention in recent years. Methods for solving QA problems based on the equivalent transformation ET principle have been recently developed. Meanwhile efficient satisfiability solvers SAT solvers have been invented and successfully applied to many kinds of problems. In this paper, we propose an ET-based low-level solution for QA problems. By slightly modifying it, we also propose a low-level solution using an all-solution SAT solver. We show that the obtained SAT-solver-based solution can also be seen as another ET-based low-level solution. Our findings clarify that the ET principle supports not only high-level computation but also low-level computation, and it provides a formal basis for correctness verification of computation in both levels.