-1
From CS2800 wiki
If is a bijection, then denotes the two-sided inverse of (which exists and is unique).
If [math]f : A \href{/cs2800/wiki/index.php/%5Cto}{\to} B [/math] is a bijection, then [math]f^{-1} [/math] denotes the two-sided inverse of [math]f [/math] (which exists and is unique).
