5 citations · 10 across the 8 of their papers we have counts for
7 papers · 1 filter
A New Decidable Class of Tuple Generating Dependencies: The Triangularly-Guarded Class
Vernon Asuncion, Yan Zhang
In this paper we introduce a new class of tuple-generating dependencies (TGDs) called triangularly-guarded TGDs, which are TGDs with certain restrictions on the atomic derivation t…
Loop Restricted Existential Rules and First-order Rewritability for Query Answering
Vernon Asuncion, Yan Zhang, Heng Zhang +2
In ontology-based data access (OBDA), the classical database is enhanced with an ontology in the form of logical assertions generating new intensional knowledge. A powerful form of…
Expressive Completeness of Existential Rule Languages for Ontology-based Query Answering
Heng Zhang, Yan Zhang, Jia-Huai You
Existential rules, also known as data dependencies in Databases, have been recently rediscovered as a promising family of languages for Ontology-based Query Answering. In this pape…
Query Answering with Inconsistent Existential Rules under Stable Model Semantics
Hai Wan, Heng Zhang, Peng Xiao +2
Traditional inconsistency-tolerent query answering in ontology-based data access relies on selecting maximal components of an ABox/database which are consistent with the ontology.…
Existential Rule Languages with Finite Chase: Complexity and Expressiveness
Heng Zhang, Yan Zhang, Jia-Huai You
Finite chase, or alternatively chase termination, is an important condition to ensure the decidability of existential rule languages. In the past few years, a number of rule langua…
Disjunctive Logic Programs versus Normal Logic Programs
Heng Zhang, Yan Zhang
This paper focuses on the expressive power of disjunctive and normal logic programs under the stable model semantics over finite, infinite, or arbitrary structures. A translation f…
Two results for proiritized logic programming
Yan Zhang
Prioritized default reasoning has illustrated its rich expressiveness and flexibility in knowledge representation and reasoning. However, many important aspects of prioritized defa…