Availability:built-in
[ISO]sort(+List,
-Sorted)True if Sorted can be unified with a list holding the
elements of List, sorted to the standard order of terms (see
section 4.7). Duplicates
are removed. The implementation is in C, using natural merge sort.117Contributed
by Richard O'Keefe. The sort/2
predicate can sort a cyclic list, returning a non-cyclic version with
the same elements.