I mean, normally, you would only do this kind of substitution if either it simplifies a lot the function you are integrating, or it simplifies a lot the region on which you are integrating.

通常，你只会在这两种情况下用替代法，或者这可以极大地简化被积函数，或者就是这可以简化，积分的上下限。

youdao

To effect the substitution, the tool amends a running kernel image with the new functions' object code and injects a jump at the head of each existing function to call its new counterpart.

为了让替换生效，工具在正在运行的内核映像中添加新的函数对象代码，然后在每个现有函数的开头注入一个跳转，从而调用函数的新实现。

youdao

A callback is used for dynamic substitution Strings in the preg_replace_callback function.

调用是用于在preg_replace_callback函数里动态地替换字符串的。

youdao