English

Translation Monoids and Recursive Evaluation in Finite Binary Algebras

Rings and Algebras 2026-04-03 v1 Combinatorics

Abstract

Let A=(A,)A=(A,\star) be a finite binary algebra, not necessarily associative. For each n1n\geq 1, every full binary bracketing on x1,,xnx_1,\dots,x_n determines an nn-ary term operation on AA, and hence an evaluation word obtained by listing its values on AnA^n in lexicographic order. This produces an mn×Cn1m^n\times C_{n-1} array, where m=Am=|A| and Cn1C_{n-1} is the (n1)(n-1)st Catalan number. We show that the recursive structure of these arrays is governed by the translation monoid T(A)=La,Ra:aAAA,La(x)=ax,Ra(x)=xa. T(A)=\langle L_a,R_a:a\in A\rangle\leq A^A, \qquad L_a(x)=a\star x,\quad R_a(x)=x\star a. More precisely, context maps arising from subterms are exactly the elements of T(A)T(A), so every element of the translation monoid occurs as a recursive block map. We also prove that rank defines a natural chain of two-sided ideals in T(A)T(A), that the minimum-rank elements form a minimal nonempty two-sided ideal, and that Green's J\mathcal J-classes are contained in rank layers. Finally, we show by example that equal rank does not determine the J\mathcal J-class in general.

Keywords

Cite

@article{arxiv.2604.01486,
  title  = {Translation Monoids and Recursive Evaluation in Finite Binary Algebras},
  author = {Volkan Yildiz},
  journal= {arXiv preprint arXiv:2604.01486},
  year   = {2026}
}
R2 v1 2026-07-01T11:50:04.033Z