It can, yes. You still have to draw a card though; you don't win the game on the spot.
July 12, 2015 9:42 p.m. Edited.
There are no "special rules" that apply to either card that would change the outcome of this scenario in a non-obvious way; it's just two cards doing exactly what they say. Leveler exiles your library, meaning that your library now contains 0 cards. The next time you would draw a card, you win the game due to Laboratory Maniac's replacement effect.
July 12, 2015 9:44 p.m.
I was just wondering specifically because the library is "removed from the game," would that mean i dont have a library to draw from? See what I mean? Lab maniac says "while your library has no cards in it," but i would have NO LIBRARY at all. so is it still ok to assume im drawing from a library that no longer exists? If leveler said remove all cards from library that would be a different story.
July 12, 2015 9:47 p.m. Edited.
Always check the Oracle text for cards in your question; old cards have sometimes received errata to make their abilities clearer.
Leveler's ability now reads, "When Leveler enters the battlefield, exile all cards from your library."
This wording makes it more obvious that the cards in your library are exiled, but that the library itself still exists.