EDB — 23N

[23N]The vice versa is also true: given \(A⊂ ℝ^ n\) a closed convex set, a convex function \(f:ℝ^ n→ℝ\) such that \(A=\{ x:f(x)≤ 0\} \) always exists: For example, you can use \(f=d_ A\), as seen in [19B]↺↻ in the previous section.