R. Pöschel

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20122026

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math.RA2026

Higher-dimensional generalized quasiorders

Andrew Moorhead, Reinhard Pöschel

It is well known that the polymorphism clone of a quasiorder is determined by its unary part, in the sense that any operation is a polymorphism if it satisfies the condition that a…

math.RA2023

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

Peter Jipsen, Erkko Lehtonen, Reinhard Pöschel

We consider $S$ -operations $f : A^{n} \to A$ in which each argument is assigned a signum $s \in S$ representing a "property" such as being order-preserving or order-reversing…

math.RA2023

Generalized Quasiorders and the Galois Connection End-gQuord

Danica Jakubíková-Studenovská, Reinhard Pöschel, Sándor Radeleczki

Equivalence relations or, more general, quasiorders (i.e., reflexive and transitive binary relations) $ρ$ have the property that an $n$ -ary operation $f$ preserves $ρ$ , i.e., $f$ i…

math.RA2020

Reflections and powers of multisorted minions

Erkko Lehtonen, Reinhard Pöschel

Classes of multisorted minions closed under extensions, reflections, and direct powers are considered from a relational point of view. As a generalization of a result of Barto, Opr…

math.RA2019

Graph quasivarieties