在这个数学问题中，你需要找出这个函数的逆运算。

In this math problem, you need to find the ___inverse operation of the function.

减法实际上是加法的逆运算。

Subtraction is the ___inverse of addition in arithmetic.

炎热与寒冷是温度的两种相反状态。

Heat and cold are the ___inverse states of temperature.