public bool Equals(Line other) { if (other is null) { return(false); } bool linesAreParallel = this.IsParallelTo(other); bool basePointIsOnLine1 = BasePoint.IsOnLine(other); bool basePointIsOnLine2 = other.BasePoint.IsOnLine(this); return(linesAreParallel && (basePointIsOnLine1 || basePointIsOnLine2)); }