Set Element - Эл-т множества

public class SetElement<T> {
    private T x;
private int depth;
private SetElement<T> parent, rootx, rooty;

public SetElement (T x) {
    this.x = x;
    depth = 0;
    parent = this;
}

public T x() {
    return x;
}

private SetElement<T> Find (SetElement<T> elem) {
    if (elem.parent == this) {
        return elem.parent;
    } else {
        elem.parent = elem.parent.Find(elem.parent);
        return elem.parent;
    }
}

public Boolean equivalent(SetElement<T> elem) {
    rootx = this.Find(this);
    rooty = elem.Find(elem);
    if (rootx == rooty) {
        return true;
    }
    return false;
}

public void union (SetElement<T> elem) {
    rootx = this.Find(this);    //union for "a" in "a.union(b)"
    rooty = elem.Find(elem);    //union for "b" in "a.union(b)"
    if (rootx.depth < rooty.depth) {
        rootx.parent = rooty;
    } else {
        rooty.parent = rootx;
        if ((rootx.depth == rooty.depth) && (rootx != rooty)) {
            rootx.depth++;
        }
    }
        return;
}
}

//========================================================================================

public class Test
{
        public static void main(String[] args)
        {
                SetElement<Integer> a = new SetElement<Integer> (0),
                        b = new SetElement<Integer> (1),
                        c = new SetElement<Integer> (2),
                        d = new SetElement<Integer> (3),
                        e = new SetElement<Integer> (4),
                        f = new SetElement<Integer> (5);
                a.union(b);
                c.union(a);
                c.union(d);
                e.union(f);
                System.out.println("" + a.x() + "=" + d.x() + ":␣" + a.equivalent(d));
                System.out.println("" + a.x() + "=" + f.x() + ":␣" + a.equivalent(f));
        }
}