English

$S$-preclones and the Galois connection ${}^S\mathrm{Pol}$-${}^S\mathrm{Inv}$, Part I

Rings and Algebras 2024-12-02 v2

Abstract

We consider SS-operations f ⁣:AnAf \colon A^{n} \to A in which each argument is assigned a signum sSs \in S representing a "property" such as being order-preserving or order-reversing with respect to a fixed partial order on AA. The set SS of such properties is assumed to have a monoid structure reflecting the behaviour of these properties under the composition of SS-operations (e.g., order-reversing composed with order-reversing is order-preserving). The collection of all SS-operations with prescribed properties for their signed arguments is not a clone (since it is not closed under arbitrary identification of arguments), but it is a preclone with special properties, which leads to the notion of SS-preclone. We introduce SS-relations ϱ=(ϱs)sS\varrho = (\varrho_{s})_{s \in S}, SS-relational clones, and a preservation property (fSϱf \mathrel{\stackrel{S}{\triangleright}} \varrho), and we consider the induced Galois connection SPol{}^S\mathrm{Pol}-SInv{}^S\mathrm{Inv}. The SS-preclones and SS-relational clones turn out to be exactly the closed sets of this Galois connection. We also establish some basic facts about the structure of the lattice of all SS-preclones on AA.

Keywords

Cite

@article{arxiv.2306.00493,
  title  = {$S$-preclones and the Galois connection ${}^S\mathrm{Pol}$-${}^S\mathrm{Inv}$, Part I},
  author = {Peter Jipsen and Erkko Lehtonen and Reinhard Pöschel},
  journal= {arXiv preprint arXiv:2306.00493},
  year   = {2024}
}

Comments

33 pages