If you fail to mate with a bishop and a knight, which is not a trivial task, even if you know the W-rule, it's still hard to get to that positon, here's a game by Stockfish A.I. lvl 8, which FAILS to mate :)
http://en.lichess.org/2gNGmX3qvLnDAnd here's an example of one way to do it right(not the shortest, but it's easier to understand by a human)
http://en.lichess.org/Gto7PHxnrqHpthank you for this post DVRazor, i didnt look at the second link, but what you've determined from stockfish's capability (at least the version on this site) is very interesting.
In the first example, stock fish doesn't realize that the mate is only possible in corners with the same color as the bishop:P
The second link is the best example of how its done, notice how the knight only goes to the seventh and fifth rank, never the sixth.
Did I just witness Stockfish doing a "awww **** it!"?
If you didn't realize, the second link is where I showed Stockfish how to play B+N :D
There is a really good explained video at the lichess video library from Jerry. I too learned from it how to checkmate with bishop and Knight. Just check it out:
http://en.lichess.org/video/r3EqM17jvOc?tags=bishop^endgame