I have a question about the proper notation of the following (simplified) example:
I want to express that I choose the value $x_i \in S$, such that $f(x_i)$ is the maximum value in the set $\{ f(x_k) \}$ where $x_k \in S$.
I thought about the following notation: Choose $x_i \in S$ such that $f(x_i)=max_{x_k \in S}(f(x_k))$.
Is it correct?