Restricted image
Set
| context | $ f:X\to Y $ |
| context | $ S\subseteq X $ |
| postulate | $ f(S)\equiv \mathrm{im}(f|_S) $ |
Discussion
The notation $f(S)$ is overloading $f$, as $S$ is not actually in the domain $X$ of $f$.
Reference
Wikipedia: Image
Parents
Subset of
Context
