English

Embeddable partial groups

Group Theory 2026-03-12 v2 Algebraic Topology Category Theory

Abstract

We record a folklore theorem that says a partial group embeds in a group if and only if each word has at most one possible multiplication, regardless of choice of parenthesization. We further investigate the partial groups which are exemplars of non-embeddability. Finally we show that a partial groupoid embeds in a groupoid if and only if its reduction embeds in a group.

Keywords

Cite

@article{arxiv.2601.19772,
  title  = {Embeddable partial groups},
  author = {Philip Hackney and Justin Lynd and Edoardo Salati},
  journal= {arXiv preprint arXiv:2601.19772},
  year   = {2026}
}

Comments

13 pages. v2: add alternate characterization of degree of universal counterexamples to section 3 (and other minor adjustments)

R2 v1 2026-07-01T09:22:33.189Z