一种扩展的动态描述逻辑语言及其Tableau算法

An extended dynamic description logic language and its Tableau algorithm

对动态系统的描述是智能领域的一个重要问题,但目前已有的动态描述逻辑语言,用不可再分的符号表示原子动作,不能区分动作类和动作实例,不足以对实际系统中的动作进行表达.因此提出了一个扩展的动态描述逻辑语言,在原子动作模态词的形式中可以表示动作的属性,从而区分了一类动作和具体动作.通过对可达关系进行限制,定义了此特殊形式模态词动作的语义.另外,还提供了此语言的Tableau算法,并证明了此算法的可终止性和完备性.

Accurate descriptions of actions in a dynamic system are essential, yet dynamic description logic languages presently available cannot meet that need because they use indivisible symbols representing atomic actions. This results in action classes and action instances being indistinguishable, with relationships between different action instances similarly inexpressible. An extended dynamic description logic language was proposed by extending the form of atomic modal operators within a parameter set. With the parameter set enabled, an atomic modal operator can represent a class of actions ; by assigning concrete values to a parameter, a sub-class of actions could be generated ; a special sub-class of actions containing only one action instance could be generated when all parameters are assigned. Hierarchy trees of actions could be developed like the concept tree. The action behaviors of the special modal operators were defined in a different manner, not merely two arbitrary possible words but those satisfying certain limitations could be reachable, and the limitations denote action behaviors. Representing actions with hierarchy trees has important meanings in action description. A sound Tableau algorithm was also provided which demonstrates the practical value of the proposed language.