Simple tasks_2

implement main
    open core,stdio

constants
    className = "main".
    classVersion = "".

class predicates
    group:(string,integer,string) nondeterm anyflow.
    ranee:().
    rock:().

clauses
    classInfo(className, classVersion).

    group("KiSH",1988,"rock").
    group("Justin Bieber",2009,"pop").
    group("DDT",1980,"rock").
    group("Kirkorov",1890,"65what").

    ranee():-
        group(X,Y,_), if Y<2000 then write(X, ", ") else end if, fail.
    ranee().

    rock():-
        group(Z,_,"rock"), write(Z,", "),fail.
    rock().

clauses
    run():-
        console::init(),
        ranee(), nl, rock(),
        succeed(). % place your own code here
end implement main

goal
    mainExe::run(main::run).