R785 - modelint/shlaer-mellor-metamodel GitHub Wiki

R785 / 1:Mc

Single Instance Flow provides zero, one or many Referenced Instance

Referenced Instance is provided by exactly one Single Instance Flow

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For a given Reference Action, a Single Instance Flow delivers an instance playing some role in that Action. If the Single Instance Flow branches and feeds the same input to more than one Reference Action it can result in multiple Referenced Instances playing potentially different roles, depending on the target Action.

On the other hand, a given instance used in a Reference Action must be delivered by a Single Instance Flow. That's because it must be exactly one instance.