---
title: "Decomposition of Declarative Knowledge Bases with External Functions"
authors:
  - "Thomas Eiter"
  - "Michael Fink"
  - "Thomas Krennwallner"
doi: ""
url: "https://ijcai.org/proceedings/2009/130"
pdf: "https://ijcai.org/proceedings/2009/0130.pdf"
venue: "Proceedings of the Twenty-First International Joint Conference on Artificial Intelligence"
year: 2009
pages: "752-757"
track: ""
keywords:
---

# Decomposition of Declarative Knowledge Bases with External Functions

Thomas Eiter, Michael Fink, Thomas Krennwallner

*Proceedings of the Twenty-First International Joint Conference on Artificial Intelligence*, pages 752-757.

## Abstract

We present a method to decompose a declarative knowledge base, given by a logic program under Answer Set Semantics with access to external sources. It overcomes the ineffectiveness of current methods due to a lack of structural information about these sources, viewed as black boxes, by exploiting independency information in accesses to them. To this end, we develop a generic notion of domain independence that allows to restrict the evaluation domain and, as a consequence, to prune unnecessary dependency assumptions between atoms. This leads to increased decomposability, which we demonstrate by an evaluation method for HEX-programs based on program rewriting. Experiments show that this may yield large performance gains. While developed for a particular formalism, the notions and ideas of this paper might be adapted to related formalisms as well.Thomas Eiter, Michael Fink, Thomas Krennwallner