> If someone copies a paragraph of my novel and claims fair use, I won't get very far on the amount-and-substantiality front by saying "but they basically took all of the part that they copied".

It's more like they copied the whole table of contents and rewrote your novel in their own words with all the headings copied verbatim. Good luck with claiming fair use on that.

I think it depends if you consider the part that was copied to be a standalone work. The fact that Google is able to create a separate implementation based only on the API design documents seems to suggest that it's a separate work that has meaning unto itself.

Would you make the same argument if you copied the entire forward from a novel?

A foreword is a lot more substantial all by itself.

Imagine if they copied the index of a textbook. It's possible to create a complete and compatible textbook using only that structure, but very few people would call it a separate work that has meaning unto itself.

In that case I think I would try the argument. But if I were on the jury I wouldn't be thinking "there's no case here".

If I understand how appealing jury decisions works, it isn't going to be anywhere near good enough for Oracle to argue that a reasonable jury might have decided the other way.

Your argument begs the question. You might as well argue "The fact that you were able to write a new novel around the word 'the' that you copied from my novel seems to suggest that the word 'the' is a separate work that has meaning unto itself."