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arXiv · 2602.22899

A note on varieties of ordered algebras

Abstract

The aim of this work is to study the notions of lax protomodular and Ord-Mal'tsev category at the level of (coherent) varieties of (pre)ordered algebras and to further compare them, as has been done in the non-ordered context. We characterise varieties of ordered algebras which are (co)lax protomodular and those which are Ord-Mal'tsev, in terms of operations of arities given by ordered sets and inequalities involving them. We exhibit examples of (co)lax protomodular non-degenerate Ord-categories, which were unknown. We prove that, for varieties of ordered algebras which are Ord-Mal'tsev categories, the order of their algebras is degenerate (i.e. is symmetric). As a consequence, the implication "protomodular => Mal'tsev" cannot be carried out to our context. The case of non-coherent ordered varieties which are Ord-Mal'tsev categories is also addressed, where we show the existence of algebras with non-degenerate order.

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BibTeXRIS

Maria Manuel Clementino amd Diana Rodelo. 2026-02-26. A note on varieties of ordered algebras. https://arxiv.org/abs/2602.22899

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