In the past three decades. a lot of Petri net-based methods have been proposed for deadlock prevention/liveness enforcing in flexible manufacturing systems (FMSs). Firstly. a plant Petri net model of an FMS is obtained and then the liveness enforcing supervisor (LES) or the controller is computed as a Petri net. https://www.ealisboa.com/mega-sale-Cuticura-Ointement-10g-amazing-save/