3 papers
math.LO2025
Splittings in varieties of logic
Brian A. Davey, Tomasz Kowalski, Christopher J. Taylor
We study splittings, or lack of them, in lattices of subvarieties of some logic-related varieties. We present a general lemma, the Non-Splitting Lemma, which when combined with som…
math.GR2025
Beyond wreath and block
Michal Botur, Tomasz Kowalski
We investigate a semigroup construction generalising the two-sided wreath product. We develop the foundations of this construction and show that for groups it is isomorphic to the…
math.LO2025
Kites and representations of pseudo MV-algebras
Michal Botur, Tomasz Kowalski
We investigate the structure of perfect residuated lattices, focussing especially on perfect pseudo MV-algebras. We show that perfect pseudo MV-algebras can be represented as a gen…