I think you run into another exception with your extended plane. It seems to me that parallel lines would still be an exception, as they now have 2 points at which they intersect, one at each end. It is only lines that are not parallel which still have only one point of intersection.
I think you run into another exception with your extended plane. It seems to me that parallel lines would still be an exception, as they now have 2 points at which they intersect, one at each end. It is only lines that are not parallel which still have only one point of intersection.