unfold Set.InjOn
case H
C : Type u_1
J : Type u_2
r : C → J → Prop
inst✝¹ : Fintype J
inst✝ : Fintype C
c : C
⊢ Set.InjOn Prod.snd ↑(Finset.filter (fun a => a.contestant = c) (A r))
case H
C : Type u_1
J : Type u_2
r : C → J → Prop
inst✝¹ : Fintype J
inst✝ : Fintype C
c : C
⊢ ∀ ⦃x₁ : C × JudgePair J⦄,
    x₁ ∈ ↑(Finset.filter (fun a => a.contestant = c) (A r)) →
      ∀ ⦃x₂ : C × JudgePair J⦄, x₂ ∈ ↑(Finset.filter (fun a => a.contestant = c) (A r)) → x₁.2 = x₂.2 → x₁ = x₂