4.1. The underlying network and queries
We can think of context- and role instances, and sets of property values, as nodes in a graph. Property value set nodes (short: property nodes) are terminal nodes. The others are connected by role binding and by the relation between a context and its roles. In Figure 1 below, we’ve drawn contexts as rectangles and nodes as circles. Nodes are drawn within the contexts they belong to, or just outside if their context is of no concern. The external node of a context is drawn outside its rectangle and is connected to it with a line.
Figure 1. The thin blue lines are part of the structure; the green lines represent query steps.
Figure 1 also shows the jumps a query makes through the graph. In fact, it shows all possible types of jumps available:
-
From a role to its binding (binding) and back (binder R1);
-
From a role to its context (context) and back (role R1);
-
From a role to a set of property values (property P).
|
Note
|
In this document, we use the terms binder and binding. We found these terms are less clear than the terms filled and filler. See Binder versus Filler terminology for an explanation.
|