We have already explored how prerequisites can be modeled in OWL using owl:allValuesFrom. At that point, we had a problem with the Open World Assumption—namely, how can we tell that all prerequisites have been satisfied if we have to assume that someone can come along and set new prerequisites at any time? We’ll use prerequisites to demonstrate a number of ways we can close the world.
As a reminder from Chapter 11, we modeled the fact that something that has all its prerequisites satisfied (i.e., selected) is an EnabledQuestion as follows:
If something satisfies the restriction (all its values are members of SelectedAnswer ...