Complement clauses: predication, modification, or reference?

[dan-zeman]

Part 3-1-1-2 is titled Processes in modification and reference and it includes example (1b) of a complement clause:

• She wanted to go to school.

Why is the going process not considered predication (which would make it inappropriate for this part, and it should be in the previous part, which states that "regardless whether they are in an independent or a dependent clause, predicated processes are always identified as events")? And if you really believe it is not predication, what do you think it is? Modification, or reference?