In Prolog, you can sort the output of a query using the built-in sort/2 predicate. This predicate takes two arguments: a list of elements and a sorted version of that list. To sort the output of a query, you can simply use sort/2 as follows:
?- sort([4,2,1,3], SortedList).
SortedList = [1,2,3,4].
In this example, the elements [4,2,1,3] are sorted in ascending order, resulting in the sorted list [1,2,3,4].