noun
sign change function
Computing term for a function that flips the sign of a value (e.g., positive to negative).
このプログラムでは符号反転機能を使って数値の符号を反転させます。
This program uses the sign change function to flip the sign of a number.
Compound of 符号 (sign), 反転 (reversal), and 機能 (function). A straightforward technical term with no obscure historical derivation.