We study graphs of (generalized) joins and intersections of finitely generated subgroups of a free group. We show how to disprove a lemma of Imrich and Müller on these graphs, how to repair the lemma and how to utilize it.
Cite this article
Sergei V. Ivanov, On joins and intersections of subgroups in free groups. J. Comb. Algebra 2 (2018), no. 1, pp. 1–18DOI 10.4171/JCA/2-1-1