Spreading nets: A uniform approach to unfoldings

This paper is devoted to the study of the notion of spread net. A spread net is a (safe) Petri nets where each place is annotated with some information, taken from a suitable information domain, about how such place can get marked. Spread nets generalize various kinds of nets used to represent the non sequential behaviours of a safe net, like unfoldings, merged processes or trellis processes. The spreading of a net may allow to produce more compact (partially unfolded) nets representing the non sequential behaviour of a net, depending on the chosen information domain. In particular in a spread net it is possible to merge not only conflicting runs, but also to partially refold time, as spread nets allow loops in time.