 [semidet]concurrent_maplist(:Goal, 
+List)
[semidet]concurrent_maplist(:Goal, 
+List)cpu_count. If 
this flag is absent or 1 or List has less than two elements, 
this predicate calls the corresponding maplist/N version using a wrapper 
based on once/1. Note 
that all goals are executed as if wrapped in
once/1 and therefore 
these predicates are semidet.
Note that the the overhead of this predicate is considerable and therefore Goal must be fairly expensive before one reaches a speedup.