exact husable ⟨U, V⟩ $ mem_filter.2 ⟨mem_univ _, hUV, h⟩
case inl
α : Type u_1
inst✝ : LinearOrder α
s U✝ V✝ : Finset α
n r : ℕ
𝒜 A : Finset (Finset (Fin n))
ih :
  ∀ (y : Finset (Finset (Fin n))),
    InvImage (fun x x_1 => x < x_1) Finset.UV.familyMeasure y A →
      Set.Sized r ↑y →
        ∃ ℬ,
          (∂ ℬ).card ≤ (∂ y).card ∧
            y.card = ℬ.card ∧
              Set.Sized r ↑ℬ ∧ ∀ (U V : Finset (Fin n)), Finset.UV.UsefulCompression U V → IsCompressed U V ℬ
h✝ : Set.Sized r ↑A
usable : Finset (Finset (Fin n) × Finset (Fin n)) :=
  filter (fun t => Finset.UV.UsefulCompression t.1 t.2 ∧ ¬IsCompressed t.1 t.2 A) univ
husable : ∀ (x : Finset (Fin n) × Finset (Fin n)), x ∉ usable
U V : Finset (Fin n)
hUV : Finset.UV.UsefulCompression U V
h : ¬IsCompressed U V A
⊢ False
no goals