2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/184731We reexamine the problem of having nonconservative equations of motion arise from the use of a variational principle. In particular, a formalism is developed that allows the inclusion of fractional derivatives. This is done within the Lagrangian framework by treating the action as a Volterra series. It is then possible to derive two equations of motion, one of these is an advanced equation and the other is retarded.To be published in Journal of Physics A: Mathematical and General, IOP Publishing Ltd. See http://www.iop.orgClassical Physicstext