It may not seem obvious until you try to implement similar functionality in
a language of your own. But the need to prefix a label with the module name
derives from the simple fact that the module is the place where the label is
defined... After you realize that, it is a simple matter to create compound
names of any depth crossing any number of module boundaries in the process.
Unless a module is "Used" in the sense of importing all of its symbols into
your current module, you must refer via the definining module name. It
really is quite simple after all...

- DM