And, of course, as with functions of one variable, we don't need things to be defined everywhere.

当然，就像单变量的函数一样，我们不需要函数在任意处都有定义。

youdao

And, of course, as with functions of one variable, we don't need things to be defined everywhere.

当然，就像单变量的函数一样，我们不需要函数在任意处都有定义。

youdao