2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/90564We involve a certain propositional logic based on ortholattices. We characterize the implicational reduct of such a logic and we show that its algebraic counterpart is the so-called orthosemilattice. Properties of congruences and congruence kernels of these algebras are described.9 pages, 2 figures; revised version for conference volume QS 2002Quantum Physicstext