2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/122802We study matrix generalizations of derivative nonlinear Schrödinger-type equations, which were shown by Olver and Sokolov to possess a higher symmetry. We prove that two of them are `C-integrable' and the rest of them are `S-integrable' in Calogero's terminology.14 pages, LaTeX2e (IOP style), to appear in Inverse ProblemsExactly Solvable and Integrable Systemstext