2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/93406It is shown that quantum-type coherence, leading to indeterminism and interference of probabilities, may in principle exist in the absence of the Planck constant and a Hamiltonian. Such coherence is a combined effect of a symmetry (not necessary physical) and semantics. The crucial condition is that symmetries should apply to logical statements about observables. A theoretical example of a non-quantum system with quantum-type properties is analysed.6 pages, postscript file also available through http://w4.lns.cornell.edu/public/CLNSQuantum Physicstext