For any injection $f$, its converse $f^{-1}$ is also a function, called its inverse.
For any injection $f$:
- \[f \circ f^{-1} = \id_{\im f}.\]
- \[f^{-1} \circ f = \id_{\dom f}.\]
For any injection $f$, its converse $f^{-1}$ is also a function, called its inverse.
For any injection $f$:
- \[f \circ f^{-1} = \id_{\im f}.\]
- \[f^{-1} \circ f = \id_{\dom f}.\]