English

Representations for the largest Extension of a closure system

Discrete Mathematics 2020-02-19 v1 Combinatorics

Abstract

We consider extension of a closure system on a finite set S as a closure system on the same set S containing the given one as a sublattice. A closure system can be represented in different ways, e.g. by an implicational base or by the set of its meet-irreducible elements. When a closure system is described by an implicational base, we provide a characterization of the implicational base for the largest extension. We also show that the largest extension can be handled by a small modification of the implicational base of the input closure system. This answers a question asked in [12]. Second, we are interested in computing the largest extension when the closure system is given by the set of all its meet-irreducible elements. We give an incremental polynomial time algorithm to compute the largest extension of a closure system, and left open if the number of meet-irreducible elements grows exponentially.

Keywords

Cite

@article{arxiv.2002.07680,
  title  = {Representations for the largest Extension of a closure system},
  author = {Karima Ennaoui and Khaled Maafa and Lhouari Nourine},
  journal= {arXiv preprint arXiv:2002.07680},
  year   = {2020}
}

Comments

16pages

R2 v1 2026-06-23T13:45:35.847Z