class IListProblem extends Object {
    IList getList() {
        return new IList(new IList(getList(), 1), 0);
    }
    // Premiere class table
    Bool contains(IList arg) {
        return ((Int)arg.head).eq(0).ite(true, this.contains(arg.tail));
    }
    // Seconde class table
    Bool contains(IList arg) {
        return ((Int)arg.head).eq(1).ite(true, this.contains(arg.tail));
    }
}