Theorem: IMOSL.IMO2017A6.good_map_eq_zero_iff (IMOSLLean4/IMO2017/A6/A6.lean)

State before:
D : Type u_1
inst✝ : DivisionRing D
f : D → D
h : good f
h0 : f 0 = 1
c : D
h1 : f = 0
⊢ 0 = 1
Tactic:
rwa [h1] at h0
State after:
no goals