> If you're really talking about bags (unordered sets), that would certainly make for an interesting filesystem since filename.txt, filemane.txt, and maletent.fix would all be the same...

I was thinking the same thing! Although if we're being pedantic, I think "bag" is an "unordered multiset". If it were just a plain unordered set, then "filename.txt" would also be the same as "filenam.txt".