*Description
An OccurrenceSpecification is the basic semantic unit of Interactions. The sequences of occurrences specified by themare the meanings of Interactions.OccurrenceSpecifications are ordered along a Lifeline .The namespace of an OccurrenceSpecification is the Interaction in which it is contained.
Associations
• event : Event [1] References a specification of the occurring event.
• covered: Lifeline [1] References the Lifeline on which the OccurrenceSpecification appears. Redefines InteractionFragment .covered.
• toBefore:GeneralOrdering [*] References the GeneralOrdering s that specify EventOcurrences that must occur before this OccurrenceSpecification.
• toAfter: GeneralOrdering [*] References the GeneralOrdering s that specify EventOcurrences that must occur after this OccurrenceSpecification.
Semantics
The semantics of an OccurrenceSpecification is just the trace of that single OccurrenceSpecification.
The understanding and deeper meaning of the OccurrenceSpecification is dependent upon the associated Message and the information
that it conveys.
Notation
OccurrenceSpecifications are merely syntactic points at the ends of Messages or at the beginning/end of an ExecutionSpecification.
Examples
(formal)
