---
title: "A New Method to Index and Query Sets"
authors:
  - "Jörg Hoffmann"
  - "Jana Koehler"
doi: ""
url: "https://ijcai.org/proceedings/1999/67"
pdf: "https://ijcai.org/proceedings/1999/0067.pdf"
venue: "Proceedings of the Sixteenth International Joint Conference on Artificial Intelligence"
year: 1999
pages: "462-466"
track: "Constraint Satisfaction"
keywords:
---

# A New Method to Index and Query Sets

Jörg Hoffmann, Jana Koehler

*Proceedings of the Sixteenth International Joint Conference on Artificial Intelligence*, pages 462-466.

## Abstract

Let us consider the following problem: Given a (probably huge) set of sets Sand a query set q, is there some set s E S such that s ~ q? This problem occurs in at least four application areas: the matching of a large number (usually several 100,000s) of production rules, the processing of queries in data bases supporting set-valued attributes, the identification of inconsistent subgoals during artificial intelligence planning and the detection of potential periodic chains in labeled tableau systems for modal logics. In this paper, we introduce a data structure and algorithm that allow a compact representation of such a huge set of sets and an efficient answering of subset and superset queries. The algorithm has been used successfully in the IPP system and enabled this planner to win the ADL track of the first planning competition.