3 papers
math.NT2026
On efficient approximation of quadratic irrationals
Peter H. van der Kamp, Anthony Overmars, Marcel Jackson +1
We provide efficient algorithms to compute convergents of quadratic irrationals. We show that for square roots, in settings where Galois' refinement of Lagrange's theorem holds, ce…
math.GR2025
The finite basis problem for additively idempotent semirings that relate to S_7
Zidong Gao, Marcel Jackson, Miaomiao Ren +1
The -element additively idempotent semiring is a nonnitely based algebra of the smallest possible order. In this paper we study the nite basis problem for some additively…
math.LO2024
Minimal signatures with undecidability of representability by binary relations
Robin Hirsch, Marcel Jackson, Jaš Šemrl
A semigroup of binary relations (under composition) on a set is \emph{complemented} if it is closed under the taking of complements within . We resolve a 1991 proble…