中文摘要：

本体描述知识的逻辑基础是描述逻辑（DL）,虽然现有DL中对概念的描述方式非常丰富,但是角色却只能是原子角色。针对角色描述能力低的问题,在现有的DLSHIQ中增加了角色表达式来对角色进行描述,证明了如果知识库中所有角色表达式都是安全的,该知识库在现有的推理机KAON2上的推理仍然是Exp-Time,提出了一种判断角色表达式是否安全的算法。

英文摘要：

Description logic is the logical foundation of ontology to describe knowledge.There are many ways to describe concepts in current description logic,but roles can only be atom roles.The role description ability is limited.To solve this problem,this paper introduces role expression in current description logic SHIQ to describe roles,and proves that if all the role expressions of the knowledge base are safe role expressions,the complexity of the reasoning with KAON2 reasoner remains in ExpTime.From this point,an algorithm is brought forward to check whether the role expression is safe.