Diagrams of queries can be made in the same way as diagrams of Prolog's
structured objects. The reason for this is simple: Prolog uses the same data structure
for both.
How queries can be comprised on more than one goal. This is important because the bodies of Prolog rules usually consist of collections of more than one Prolog goal. In other words, you are well on the way to writing Prolog rules. This part also shows the use of the Anonymous Variable.
