Кто на чем ездит.

man("Alex").
man("Boria").
man("Vitte").
bus(X):-man(X), X<>"Alex",X<>"Vitte".
troll(Y):-man(Y), not(bus(Y)),Y<>"Alex".
tram(Z):-man(Z), not(troll(Y)), not(bus(Y)).

predicates
nondeterm man(string).
nondeterm solve(string,string,string).
 
clauses
man("Alex").
man("Boria").
man("Vitte").
solve(Bus,Troll,Tram):-
    man(Bus),Bus<>"Alex",
    man(Troll),Troll<>Bus,Troll<>"Boria",Troll<>"Alex",
    man(Tram),Tram<>Bus,Tram<>Troll.
 
goal
solve(X,Y,Z).

domains
name=string
list=integer*
predicates
nondeterm check(list[name,name,name]).
nondeterm get_solution(name).
clauses
check(1,[_,Alex,_]).
check(1,[_,_,Alex]).
check(2,[Boria,_,_]).
check(2,[_,_,Boria]).
check(3,[Vitte,_,_]).
check(3,[_,Vitte,_]).
get_solution(L):-shuffle([bus,troll,tram]),
check(1,L),
check(2,L),
check(3,L).

goal
solve(X,Y,Z),write("Bus: ",X,"\nTroll: ",Y,"\nTram: ",Z).