Theorem: Matroid.empty_skew (Matroid/Modular.lean)

State before:
ι : Type u_1
α : Type u_2
M : Matroid α
B I J X X' Y Y' F : Set α
Xs Ys Js Is : ι → Set α
i j : ι
e f : α
hX : X ⊆ M.E
⊢ M.Skew ∅ X
Tactic:
rw [skew_iff_contract_restrict_eq_restrict, contract_empty]
State after:
no goals