1. This paper is devoted to a proof of decidability on consistent structure and gives a rapid decision method.

2. The decidability of system M can thus be derived from the finite model property.

3. The decidability of the model is proven and a decidability algorithm is presented.

4. A model verification algorithm based on DTMA and the subset of DTMA modal logic is devised, and the decidability of the model verification is proved.

5. Condensing is one important type of redundancy elimination. We first consider the decidability and complexity of this problem, and then gives a polynomial algorithm of its sub-problem.

6. This thesis fully uses the expressing and reasoning ability of description logic and applies it in the spatial reasoning to increase the accuracy and decidability of the reasoning.

7. A formal semantics is given. We prove 79's soundness, consistency, completeness[sentencedict .com], and decidability with respect to the semantics.

8. We present a dense timed interval temporal logic and exploit the decidability problem of DTITL.

9. In his fictions, the destiny is represented by the mysterious nature, the decidability and comeuppance, contingency and coincidence, instinct and desire.

10. The concept of algorithm is also used to define the notion of decidability.