Anti places/limit places

Anti places/limit places

Often one would like to limit the capacity for a place, for example, to model a network buffer or simply to make the net finite to facilitate the generation of state spaces. Unfortunately, CPN Tools does not support this concept, but this can easily be modeled using the concept of anti-places. An anti-place is a place corresponding to the original place, where for each arc […]

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Inhibitor arcs

Inhibitor arcs

Introduction CPN Tools does not natively support inhibitor arcs. It is however possible to simulate the behavior of inhibitor arcs. This can be done in at least two different ways. It can be done using lists. This way is a bit more cumbersome, but can be made to work in all cases. Simulation of inhibitor arcs can also be done using anti-places. This is a […]

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Queues and stacks

Queues and stacks

It is often nice to be able to simulate a queue or stack discipline for places, e.g. for communication over a TCP channel. Alas, CPN Tools does not currently support this, but this is easy done by the modeler. Example This is a very simple model of a sender and a receiver. The sender, sends packages onto a network. The receiver receives packages from the […]

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Graphical feedback

Graphical feedback

Several kinds of graphical feedback are used to provide different kinds of information when editing and analyzing a CP-net. Speech bubbles Status bubbles Auras Changing cursor icon Speech bubbles A speech bubble is a yellow rectangle that provides context-sensitive information. Some speech bubbles appear automatically, while others appear after a slight delay after the cursor is moved over an appropriate object. For example, moving the […]

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Syntax checking

Syntax checking

Syntax check and color auras CPN Tools automatically syntax checks your nets as you create them or when you load in a net. You can see by color indications how far the check has gotten. The color indications are shown in the index, underlining the name of the page where the color belongs. If the page is open in a binder, the color is also […]

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Exceptions

Exceptions

Exceptions may be raised during syntax checking, code generation, simulation, or state space analysis. As CPN ML builds on top of Standard ML, we distinguish between exceptions that are declared as part of CPN ML and Standard ML exceptions. CPN ML exceptions The following exceptions are declared as part of CPN ML. InternalError str Indicates that a serious error occurred during syntax checking, code generation, […]

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