selection differential

• 选择的微分

selection differential的用法和样例：

例句

1. Therefore the operator we seek is the differential of a spike.
   因此，我们欲求的因子是一个单位脉冲的微分。
2. Very general systems of differential equations can be reduced to the normal form.
   形式很普通的微分方程组可以化为正规的形式。