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There are some differences to my proposal, however. Whereas I completely abandon "file names" in favour of a unique set of categories for identifying files, LFS actually retains file names, but replaces the directory name components of the path to a file with a boolean expression. It's only a superficial difference, though, but in my humble opinion, the LFS approach seems more complicated here than necessary (although, on the other hand, sometimes it might actually be useful to have a name for each file). But, indeed, at the implementation level the distinguished file name seems to disappear. A more important difference is that LFS allows both conjunctions and disjunctions as well as negations for looking up files, unlike my proposal.