Efficient Answer Enumeration in Description Logics with Functional Roles -- Extended Version

TL;DR

This paper presents a method for efficiently enumerating answers to ontology-mediated queries in description logics with functional roles, achieving linear preprocessing and constant delay under specific acyclicity conditions.

Contribution

It introduces a novel approach for answer enumeration in description logics with functional roles, establishing conditions for linear preprocessing and constant delay enumeration.

Findings

Enumeration is possible with linear preprocessing and constant delay.

The approach applies to both complete and partial answers.

Matching lower bounds are provided for self-join free queries.

Abstract

We study the enumeration of answers to ontology-mediated queries when the ontology is formulated in a description logic that supports functional roles and the query is a CQ. In particular, we show that enumeration is possible with linear preprocessing and constant delay when a certain extension of the CQ (pertaining to functional roles) is acyclic and free-connex acyclic. This holds both for complete answers and for partial answers. We provide matching lower bounds for the case where the query is self-join free.