FAQ

Petri nets are a mathematical modelling language to study concurrent and distributed systems. Graphically, a Petri net is a directed bipartite graph, in which there are two subsets of nodes: that of transitions (represented as rectangles) and that of places (represented as circles).

A place represents some kind of resource repository: a place can contain one or more tokens (black bullets). A token represents a resource of a certain kind.

A transition is an activity. The incoming places of a transition express the resources needed to execute the transition. The execution of the transition, called firing, moves token from the incoming places to the outgoing places.

A persistent place is a special kind of place with a particular semantics. Graphically, it is represented as a double circle. Once a token is in the persistent place, it will remain in the place forever. A transition can only read the tokens from persistent places for its execution without consuming it
An s-cell (Structural Branching Cell) is a subset of nodes and it is uniquely determined by a set of transitions that are equivalent to each other according to an equivalence relation. That equivalence relation is induced by the least preorder that includes immediate conflict and causality. Intuitively, an s-cell is a net fragment that cannot be decomposed in series or parallel. Each s-cell exposes a set of alternatives, called transactions, that can be equipped with an indipendent probability distribution.
Dynamic nets are Petri nets in which the firing of a transition can add new nodes to the net. In our case, the firing of a transition can only increase the set of transitions.
REMCONF imposes some restrictions on the Petri nets taken in input. In fact, the input Petri net must be acyclic and its places must have at most one incoming arc. Actually there are no results that deal with confusion for any largerg class of Petri nets.
A future work could be that of studying how to remove confusion from any Petri net.