This is a very nicely done site and is great for getting the topic started. However it looks to be extreamy flawed
If every combination were generated it would have to be done in sequence. There for book “aaaaaaaaa” should exist on wall one shelf one book one. It does not
Don’t call others idiots just like that. I think it’s a good question. How does the library gurantee that every possible pseudorandom permutation appears strictly once? If it were to apear even once more logically it would take some other book’s place and the library would not be complete. In fact this specefic implementation of the library does not gurantee that every possible book is in it, only that every possible page is. That’s also the reason why in the search option you can search at most 3200 characters – exactly the number of characters in a single page.
So to answer the original question; you are right, not every book is in this library 🙁