exact Or.inl ⟨by simp, by simp⟩
case inl.intro
α : Type u_1
β : Type u_2
γ : Type u_3
α₁ : Type u_4
α₂ : Type u_5
α₃ : Type u_6
M : Matroid α
N : Matroid β
B I D X Y : Set α
⊢ (emptyOn α)✶ ≂ (emptyOn β)✶
no goals