---
title: "The Levelwise Version Space Algorithm and its Application to Molecular Fragment Finding"
authors:
  - "Luc De Raedt"
  - "Stefan Kramer"
doi: ""
url: "https://ijcai.org/proceedings/2001/117"
pdf: "https://ijcai.org/proceedings/2001/0117.pdf"
venue: "Proceedings of the Seventeenth International Joint Conference on Artificial Intelligence"
year: 2001
pages: "853-861"
track: ""
keywords:
---

# The Levelwise Version Space Algorithm and its Application to Molecular Fragment Finding

Luc De Raedt, Stefan Kramer

*Proceedings of the Seventeenth International Joint Conference on Artificial Intelligence*, pages 853-861.

## Abstract

A tight integration of Mitchell’s version space algorithm with Agrawal et al.’s Apriori algorithm is presented. The algorithm can be used to generate patterns that satisfy a variety of constraints on data. Constraints that can be imposed on patterns include the generality relation among patterns and imposing a minimum or a maximum frequency on data sets of interest. The theoretical framework is applied to an important application in chemo-informatics, i.e. that of finding fragments of interest within a given set of compounds. Fragments are linearly connected substructures of compounds. An implementation as well as preliminary experiments within the application are presented.