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arXiv · 2512.04762

Maehara Interpolation in Extensions of R-mingle

Wesley Fussner·Krzysztof Krawczyk
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Abstract

We show that there are exactly five quasivarieties of Sugihara algebras with the amalgamation property, and that all of these have the relative congruence extension property. As a consequence, we obtain that the amalgamation property and transferable injections property coincide for arbitrary quasivarieties of Sugihara algebras. These results provide a complete description of arbitrary (not merely axiomatic) extensions of the logic R-mingle that have the Maehara interpolation property, and further demonstrates that the Robinson property and Maehara interpolation property coincide for arbitrary extensions of R-mingle. Further, we show that the question of whether a given finitely based extension of R-mingle has the Maehara interpolation property is decidable.

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Wesley Fussner, Krzysztof Krawczyk. 2025-12-04. Maehara Interpolation in Extensions of R-mingle. https://arxiv.org/abs/2512.04762

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