Yes!

A fun anecdote from my defense was that this element of logic "did not exist before some time" or something.

One of my citations was a book from like, the 1700's or something, and it absolutely blew away one of the committee members that I'd found it. He asked me "how on earth did you find this reference?" and I just told him that I look at all the math/logic libraries in Boston I had access to, I looked up all their logic books that predated the cut off I was looking for, and I skimmed them.

I didn't even have to leave my university's library, because one of the first five books had the counter-factual I was looking for. Sure, it was a rare book and I had read it in a special room, but it wasn't particularly hard to find.

Before that defense, I was 100% the only person alive with that information.