While [Plan 9's] 'mount' connects a new service to … As an example, … [the following assembles], under a single directory /bin, all of … : bind("/sparc/bin", "/bin", MRELPL); bind("/usr/rob/sparc/bin", "/bin", MAFTER); … The ability to build such union directories obviates … 'bind' has a local scope, applying only to … the kernel's representation of a bind is identical … upon the 'fromfile'.
Google-1
Google-2
Copyright clearance needed for quotation.