Fist of all: Most pages of a book don’t start with a complete sentence. Should the sentence fragment starting at the top of the page be counted as the first sentence, or not? Please clarify.
I’m going to go with the interpretation of fifth sentence to mean fifth complete sentence. Read on and guess which book happened to be sitting closest to my computer:
Then *pfa is a recognized as a dcl, so (*pfa) is also a direct-dcl. Then (*pfa)() is a direct-dcl and thus a dcl. We can also illustrate the parse with a parse tree like this (where direct-dcl has been abbreviated to dir-dcl):