public void AddTo(BigNumber num) { if (num.Sign != this.Sign) { int compare = num.CompareAbsolute(this); if (compare < 0) { AbsoluteSubtractFrom(num, this); this.Sign = num.Sign; } else if (compare > 0) { AbsoluteSubtractFrom(this, num); this.Digits = num.Digits; } else { this.Clear(); this.Sign = enumSign.Positive; } } else { AbsoluteAddTo(num); } }