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+A directory of ARF files is called a module, and the basename of the directory
+is that module's name. When a module is used in code, it will be referred to by
+this name. Modules include other modules include other modules by specifying
+their relative path (beginning with ./) or just by giving the path of the module
+relative to a package install location (maybe /usr/include/arf or ~/.arf or
+something).
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