rw [simplification_eq_self_iff]
α : Type u_1
M✝ N : Matroid α
e f g : α
I X P D : Set α
M : Matroid α
⊢ M.simplification.simplification = M.simplification
α : Type u_1
M✝ N : Matroid α
e f g : α
I X P D : Set α
M : Matroid α
⊢ M.simplification.Simple