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UML Diagrams
Zicomi Systems publishes some UML example diagrams online from the world famous UML dictionary.
Version 2.5 Released
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A junction is a kind of pseudostate that is used to merge and (or) split one or more transitions between states creating complex paths. They can take one or more incoming transitions and have one or more outgoing transitions. The do not create concurrent transitions but their result is the firing of a single outgoing transition. The outgoing transitions are typically guarded and these conditions are evaluated statically.


A junction is a semantically weak element that is used to merge and split transitions in a state machine. They can have one or more incoming transitions and one or more outgoing transitions. They are most commonly used to merge a number of transitions back together so as to form a single transition. When the junction is used to split one or more incoming transitions into one or more outgoing transitions it is common to used the predefined guard 'else' on one (and only one) outgoing transition to ensure that at least one transition is fired otherwise the machine will stall. When used to split a single incoming transition they have similar (but weaker) semantics to a choice pseudostate. The guards in a junction are evaluated statically whereas in a choice they are evaluated dynamically.

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