congr
n : ℕ
f : Bump ℝ
K : Set ℝ
hK : IsCompact K
⊢ sSup ((fun x => ↑(absNthDeriv n f x)) '' K) = sSup ((fun a => ↑a) '' (absNthDeriv n f '' K))
case e_a
n : ℕ
f : Bump ℝ
K : Set ℝ
hK : IsCompact K
⊢ (fun x => ↑(absNthDeriv n f x)) '' K = (fun a => ↑a) '' (absNthDeriv n f '' K)