2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/33072We give an evolving algebra solution for the well-known railroad crossing problem and use the occasion to experiment with agents that perform instantaneous actions in continuous time and in particular with agents that fire at the moment they are enabled.See also the web site at http://www.eecs.umich.edu/gasm/Software EngineeringD.2.4text