# CONDITION/EVENT (C/E) - SYSTEMS

## Definition and Transition Rule

(according to [bd92])

### Structural Properties

**pureness:** according to point 3 in the definition
**simplicity:** a C/E System has to be simple by definition
**1-liveness:** according to point 3 each event is 1-live
**backward and forward reachability:**

Transitions in a C/E System can occur, individually or concurrently, backward and forward, and the resulting full reachability class of the system is greater than the union of the backward and forward reachability classes. Full reachability is an equivalence relation, thus whatever case can be chosen to represent the reachability class. On the contrary; if a net system evolves only forward, reachability is no longer an equivalence relation and the choice of a distinguished case at the initial one changes the reachability class.

## Sample Net

(from [rei87])

## Tools

MOBY is a simulation tool based on Smalltalk.

POSES is a simulation and development system.

HyperNet, a modelling and analysis tool

WinPetri, a Petri Net Tool for Windows
## References

- H. J. Genrich, K. Lautenbach, P. S. Thiagarajan:
`Elements of general Net Theory` [glt80]
- E. Best, C. Fernandez:
`Notations and Terminology on Petri Net Theory` [bf86]
- L. Bernardinello, F. De Cindio:
`A survey of Basic Net Models and Modular Net Classes` [bd92]

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