2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/26904Recently it has been suggested by A. M. Tsvelik that quantum S=1/2 antiferromagnet can be described by the Majorana fermions in an irreducible way and without any constraint. In contrast to this claim we shall show that this representation is highly reducible. It is a direct sum of four irreducible fundamental representations of $su(2)$ algebra.5 pp., plain Latex, comment on cond-mat/9206007Condensed Mattertext