Type-elimination-based reasoning for the description logic SHIQbs using decision diagrams and disjunctive datalog
This work addresses reasoning challenges in description logics for knowledge representation, but it appears incremental as it builds on existing reductions and compilation techniques.
The paper tackles reasoning in the description logic SHIQbs with DL-safe rules by proposing a type-elimination-based method that converts knowledge bases into OBDDs and disjunctive Datalog, achieving worst-case optimal combined and data complexity.
We propose a novel, type-elimination-based method for reasoning in the description logic SHIQbs including DL-safe rules. To this end, we first establish a knowledge compilation method converting the terminological part of an ALCIb knowledge base into an ordered binary decision diagram (OBDD) which represents a canonical model. This OBDD can in turn be transformed into disjunctive Datalog and merged with the assertional part of the knowledge base in order to perform combined reasoning. In order to leverage our technique for full SHIQbs, we provide a stepwise reduction from SHIQbs to ALCIb that preserves satisfiability and entailment of positive and negative ground facts. The proposed technique is shown to be worst case optimal w.r.t. combined and data complexity and easily admits extensions with ground conjunctive queries.