2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/171990A counterexample to the conjecture that the automorphisms of an arbitrary Arveson system act transitively on its normalized units.v3: mistakes corrected in formulas (pp. 9, 11, 16, 18, 23, 24, 27, 30) and refs (pp. 2, 6, 28, 29, 30)Operator AlgebrasProbability46L55; 60G99text