Involution (mathematics)

In mathematics, "involution" refers to a function that, when applied twice, returns the original value. Formally, if \( f \) is an involution, then: \[ f(f(x)) = x \] for all \( x \) in its domain. This property means that the function is its own inverse. Involutions can be found in various mathematical contexts, including algebra, geometry, and operators in functional analysis. ### Examples of Involutions 1.