Availability:built-in
mutex_statisticsPrint usage statistics on internal mutexes and mutexes associated with 
dynamic predicates. For each mutex two numbers are printed: the number 
of times the mutex was acquired and the number of collisions: 
the number of times the calling thread has to wait for the mutex. The 
output is written to current_output and can thus be 
redirected using with_output_to/2.