English

Closed classes of functions, generalized constraints and clusters

Rings and Algebras 2016-11-22 v1

Abstract

Classes of functions of several variables on arbitrary non-empty domains that are closed under permutation of variables and addition of dummy variables are characterized in terms of generalized constraints, and hereby Hellerstein's Galois theory of functions and generalized constraints is extended to infinite domains. Furthermore, classes of operations on arbitrary non-empty domains that are closed under permutation of variables, addition of dummy variables and composition are characterized in terms of clusters, and a Galois connection is established between operations and clusters.

Keywords

Cite

@article{arxiv.0810.3212,
  title  = {Closed classes of functions, generalized constraints and clusters},
  author = {Erkko Lehtonen},
  journal= {arXiv preprint arXiv:0810.3212},
  year   = {2016}
}

Comments

21 pages

R2 v1 2026-06-21T11:32:10.113Z