What is the length of the line segment between points A and B on a number line, where A = 0 and B = 1? Is it exactly 1? Perhaps I am thinking about it in an incorrect manner, but it seems to me that 1 is distance from A to B, not taking into account that infinitesimally small width of point A and B. Or is it that the widths of A and B are so infinitely small that they're essentially 0?