Utilises the uuid/1 predicate which never fails; the implementation relies on that prerequisite. Nor does uuid/1 automatically generate a randomly unique identifier. The implementation repeats on failure to find a module that does not already exist. If the generation of a new unique module name always fails, the predicate will continue an infinite failure-driven loop running until interrupted within the calling thread.

The predicate allows for concurrency by operating a mutex across the clauses testing for an existing module and its creation. Succeeds only for mode (-).