2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/153576The von Neumann type subsystems of $q$-deformed coherent states are considered. The completeness of such subsystems is proved.LateX file. 28 pages. This is slightly modified version of paper published in Helv. Phys. Acta 68, 554 (1996)Quantum Algebratext