Things would have been the same.
People say that many things had been lost but I have my doubts that it either wasn't recovered or would have mattered.
Say for instance the Newton's three laws were in a book on that library. Would this be a huge discovery? Sure. But it wouldn't change history.
really the biggest losses were books about practices like the text the emperor Claudius wrote about the Etruscans. If we had that it might answer some of the questions we have about them.
What really set humans back wasn't losing the libraray. It was losing the Romen Empire.
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If there are single battles in generation 7 I'll close my account.
http://www.gamefaqs.com/boards/792673-pokemon-omega-ruby/70118926