English

Learning Unions of k-Testable Languages

Formal Languages and Automata Theory 2018-12-21 v1

Abstract

A classical problem in grammatical inference is to identify a language from a set of examples. In this paper, we address the problem of identifying a union of languages from examples that belong to several different unknown languages. Indeed, decomposing a language into smaller pieces that are easier to represent should make learning easier than aiming for a too generalized language. In particular, we consider k-testable languages in the strict sense (k-TSS). These are defined by a set of allowed prefixes, infixes (sub-strings) and suffixes that words in the language may contain. We establish a Galois connection between the lattice of all languages over alphabet {\Sigma}, and the lattice of k-TSS languages over {\Sigma}. We also define a simple metric on k-TSS languages. The Galois connection and the metric allow us to derive an efficient algorithm to learn the union of k-TSS languages. We evaluate our algorithm on an industrial dataset and thus demonstrate the relevance of our approach.

Keywords

Cite

@article{arxiv.1812.08269,
  title  = {Learning Unions of k-Testable Languages},
  author = {Alexis Linard and Colin de la Higuera and Frits Vaandrager},
  journal= {arXiv preprint arXiv:1812.08269},
  year   = {2018}
}
R2 v1 2026-06-23T06:50:22.457Z