Availability:built-in
exited(Term) as 
result state for thread_join/2. 
If the thread has the attribute
detached(true) it terminates, but its exit status cannot be 
retrieved using thread_join/2, 
making the value of Term irrelevant. The Prolog stacks and C 
thread are reclaimed.
The current implementation does not guarantee proper releasing of all mutexes and proper cleanup in setup_call_cleanup/3, etc. Please use the exception mechanism (throw/1) to abort execution using non-standard control.