simp only [ne_eq]
case inr
R : Type u_1
inst✝¹ : CommSemiring R
inst✝ : PerfectRing R
h✝ : ¬ringChar R = 0
⊢ (fun x => x ^ ringChar R) (Function.surjInv (_ : Function.Surjective fun x => x ^ ringChar R) 0) =
    (fun x => x ^ ringChar R) 0
case inr
R : Type u_1
inst✝¹ : CommSemiring R
inst✝ : PerfectRing R
h✝ : ¬ringChar R = 0
⊢ Function.surjInv (_ : Function.Surjective fun x => x ^ ringChar R) 0 ^ ringChar R = 0 ^ ringChar R