With the readable file spec
The files '/home/muser/a' and '/home/muser/foo/b' are considered readable, but the files '/home/muser/b' and '/home/muser/c' are not. This is due the following facts:
'/home/muser/a' is best matched by '+/home/muser/a';
'/home/muser/foo/b' is best matched by '+/home/muser/...';
'/home/muser/b' is best matched by '-/home/muser/*';
'/home/muser/c' is best matched by both '-/home/muser/c' and '+/home/muser/c', but the '-' spec takes precedence.