Definition 1. An involutory function or involution is a function $f : X \to Y$ such that
\[f(f(x)) = x\]for all $x \in X$.
Pub Apr 18, 2026 Up Jun 10, 2026
Definition 1. An involutory function or involution is a function $f : X \to Y$ such that
\[f(f(x)) = x\]for all $x \in X$.