Свой собственный дедушка, Prolog 7.2

include "ded.inc"
predicates
nondeterm family(symbol, symbol)
nondeterm parent(symbol, symbol)
nondeterm male(symbol) 
nondeterm female(symbol)
nondeterm father(symbol, symbol)
nondeterm grandfather(symbol,symbol)
clauses
male(john). 
male(ian). 
female(jane).         
female(kate).         
family(john, jane). 
family(ian, kate).
parent(ian, john). 
parent(jane, kate). 
parent(ian, jake).     
parent(john, keegan). 
parent(X, Y) :- family(X, Z), parent(Z, Y).
parent(X, Y) :- family(Z, X), parent(Z, Y).
father(X, Y) :- parent(X, Y), male(X). 
grandfather(X, Y) :- father(X, Z), parent(Z, Y).
goal
grandfather(john,john).
 
Нужно адаптировать ее под 7.2, но у меня выдает ошибку.
Код main.cl
class main
    open core
predicates
    classInfo : core::classInfo.
    family : (symbol , symbol ) procedure(i,o).
    parent : (symbol  , symbol ) procedure(i,i).
    male : (symbol ) procedure(i).
    female : (symbol ) procedure(i).
    father : (symbol , symbol ) procedure(i,o).
    grandfather : (symbol ,symbol ) procedure(i,i).
predicates
    run : core::runnable.
end class main
 
Код main.pro:
implement main
    open core
constants
    className = "main".
    classVersion = "".
clauses
    classInfo(className, classVersion).
    male("john"). 
    male("ian").
    female("jane").
    female("kate").
    family("john"," jane").
    family("ian", "kate").
    parent("ian", "john").
    parent("jane", "kate").
    parent("ian", "jake").
    parent("john", "keegan").
    parent(X, Y) :- family(X, Z), parent(Z, Y).
    father(X, Y) :- parent(X, Y), male(X).
    grandfather(X, Y) :- father(X, Z), parent(Z, Y).
clauses
    run():-
        console::init(),
        grandfather("john", "john"),
        succeed(). 
end implement main
goal
    mainExe::run(main::run).