domains
    x = integer
    l = integer*
    
predicates
    reverse(l,l)
    concatenate(l,l,l)
    
clauses
    concatenate([],List,List).
    
    concatenate([X|List1],List2,[X|List3]) :-
        concatenate(List1,List2,List3).
        
    reverse([],[]).
    
    reverse([Head|Tail],List) :-
        reverse(Tail,List1),
        concatenate(List1,[Head],List).
        
Output :

Goal: reverse([2,1,3,4],List)
List=[4,3,1,2]
1 Solution