public abstract class SchemeNumber extends SchemeObject implements Comparable
{
    public abstract SchemeNumber add(SchemeNumber n);
    public abstract SchemeNumber subtract(SchemeNumber n);
    public abstract SchemeNumber multiply(SchemeNumber n);
    public abstract SchemeNumber negate();
    public abstract SchemeNumber divide(SchemeNumber n);
    public abstract double doubleValue();
    public abstract int compareTo(SchemeNumber n);

    public int compareTo(Object o)
    {
	return compareTo((SchemeNumber)o);
    }

    
}