Role instances can be dynamically created during execution of the UOL as defined by LD.
When doing so, the engine enforces the rules implied by both the model and the UOL preventing the system getting into a state not allowed by the UOL.
Another issue to notice in Table 1 is that a new type of property, the global UOL property, has been added in addition to the ones that are defined in LD.
We assume that the UOL for which this state machine is drawn, contains a conditional construct that states that setting property x to value y should result in the completion of learning activity Z.
The input and output alphabet will vary of course from one UOL to another as the properties defined in the UOL will differ and therefore also the potential events.
A publication is the result of preprocessing a UOL. We have already seen that the properties and event handling mechanisms depend on the outcome of this process.
The first step of the publication process is to check the UOL validity.
As noted earlier, global UOL properties are used to store these small XML documents.
Another important result of the parsing process is the store containing rules that should be applied to a UOL. The event dispatcher retrieves these entries to determine what actions need to be taken when an event occurs.