have h2 := good_shift h0 h1
R : Type u_1
F : Type u_2
inst✝ : Field F
h : 2 = 0
f : F → F
h0 : good f
h1 : f 0 = 1
⊢ Injective f
R : Type u_1
F : Type u_2
inst✝ : Field F
h : 2 = 0
f : F → F
h0 : good f
h1 : f 0 = 1
h2 : ∀ (x : F), f (x + 1) + 1 = f x
⊢ Injective f