ThmDex – An index of mathematical definitions, results, and conjectures.

Formulation F10554 on R352: Inverse image of image

F10554

Formulation 0

Let $f : X \to Y$ be a D18: Map such that

(i)	$A \subseteq X$ is a D78: Subset of $X$

Then \begin{equation} f^{-1}(f A) = A \end{equation}