domains
    x = integer
    l = integer*
    
predicates
    maxlist(l,x)
    max(x,x,x)
    
clauses
    max(X,Y,Max) :-
        X > Y,!,
        Max = X.
        
    max(X,Y,Max) :-
        Max = Y.
        
    maxlist([],0).
    maxlist([X],X).
    maxlist([X,Y|List],Max) :-
        max(X,Y,Max1),
        maxlist([Max1|List],Max).
        
Output :

Goal: maxlist([],M)
M=0
1 Solution

Goal: maxlist([-1,-2,-3,-4],M)
M=-1
1 Solution

Goal: maxlist([-8,-1,10,-2,-3,-4],M)
M=10
1 Solution