Nor have we completed the inventory of meanings.

[suprunp]

1.15 Nor have we completed the inventory of meanings.
(A comprehensive grammar of the English language)
These are the words the section 1.15 begins with (page 13).

In the preceding section 1.14 the authors talk about the first meaning of 'grammar' that is identified by lay native speakers with inflections.

In 1.15 the authors talk about the second meaning of 'grammar' that is identified by lay native speakers with syntax.

But I do not see any negative statements in the section 1.14 that could probably precede 'Nor have we [...]'.

Is it just an intensifier?
Does it have something to do with this usage of 'nor'?

3. (used after an affirmative clause, or as a continuative, in the sense of and not)
Random House Webster's Unabridged Dictionary

Thanks.

[5jj]

3. (used after an affirmative clause, or as a continuative, in the sense of and not)
Random House Webster's Unabridged Dictionary

That works. 'And we have not completed the inventory...