Artificial Intelligence ( IF 14.4 ) Pub Date : 2022-10-21 , DOI: 10.1016/j.artint.2022.103808 Víctor Gutiérrez-Basulto, Yazmín Ibáñez-García, Jean Christoph Jung, Filip Murlak
A prime application of description logics is ontology-mediated query answering, with the query language often reaching far beyond instance queries. Here, we investigate this task for positive existential two-way regular path queries and ontologies formulated in the expressive description logic , where denotes the extension of the basic description logic with transitive roles () and qualified number restrictions () which can be unrestrictedly applied to both non-transitive and transitive roles (). Notably, the latter is usually forbidden in expressive description logics. As the main contribution, we show decidability of ontology-mediated query answering in that setting and establish tight complexity bounds, namely 2ExpTime-completeness in combined complexity and coNP-completeness in data complexity. Since the lower bounds are inherited from the fragment , we concentrate on providing upper bounds. As main technical tools we establish a tree-like countermodel property and a characterization of when a query is not satisfied in a tree-like interpretation. Together, these results allow us to use an automata-based approach to query answering.
中文翻译:
回答由不受限制的 SQ 本体介导的常规路径查询
描述逻辑的主要应用是本体介导的查询回答,查询语言通常远远超出实例查询。在这里,我们针对正存在的双向正则路径查询和在表达性描述逻辑中制定的本体研究此任务, 在哪里表示基本描述逻辑的扩展具有传递角色() 和限定数量限制 () 可以不受限制地应用于非传递性和传递性角色 ()。值得注意的是,后者通常在表达性描述逻辑中被禁止。作为主要贡献,我们展示了本体介导的查询回答在该设置中的可判定性,并建立了严格的复杂性界限,即组合复杂性中的2ExpTime完整性和数据复杂性中的coNP 完整性。由于下界是从片段继承的,我们专注于提供上限。作为主要的技术工具,我们建立了一个树状反模型属性,并在树状解释中不满足查询时的特征。总之,这些结果使我们能够使用基于自动机的方法来进行查询回答。