Is if there's any
grammatical in the sentence below?
I'll need to look up Huddleston and Pullum's opinion on this issue, if there's any.
The source is the last sentence of an answer on this website.
To me, there is
can't be contracted here. But I can't explain why. Is it because the verb to be
needs to stand on its own here? Is there some rule that says this?
What if the writer added a few words like in this sentence:
I'll need to look up Huddleston and Pullum's opinion on this issue, if there's any to be found.
Does that make it grammatical? If so, why? Does using a second to be
have anything to do with it?