A digit, usually zero, produced during the normalizing of a floating-point number, and inserted during a left shift operation into the fixed point part. 在浮点数的规格化过程中产生的，在左移位操作中插入定点部分的数字，该数字通常为零。
A plane curve formed by the locus of points equidistant from a fixed line and a fixed point not on the line. 抛物线到一固定直线和不在直线上某一固定点等距的点的轨迹所形成的平面曲线
