exact Or.inr rfl
case refine_2.mk.inr
α : Type u_1
M : Matroid α
I F✝ X Y F' F₀ F₂ P L H H₁ H₂ H' B C K : Set α
e f : α
hF₀ : M.Flat F₀
F : Set α
hF : M.Flat F
h₀ : F₀ ⊆ F
x✝ : M.Flat F₀ ∧ M.Flat F ∧ F₀ ⊂ F ∧ ∀ (F_1 : Set α), M.Flat F_1 → F₀ ⊆ F_1 → F_1 ⊆ F → F_1 = F₀ ∨ F_1 = F
hF₁ : M.Flat F
hss : F₀ ⊂ F
hforall : ∀ (F_1 : Set α), M.Flat F_1 → F₀ ⊆ F_1 → F_1 ⊆ F → F_1 = F₀ ∨ F_1 = F
h₁ : F ⊆ F
⊢ ⟨F, hF⟩ = ⋯.toFlatOf ∨ ⟨F, hF⟩ = ⋯.toFlatOf
no goals