Theorem: Matroid.contract_eq_loopyOn_of_spanning (Matroid/Minor/Basic.lean)

State before:
α : Type u_1
M M' N : Matroid α
e f : α
I J R B X Y Z K E C : Set α
h : M.Spanning C
⊢ M ／ C = loopyOn (M.E \ C)
Tactic:
rw [eq_loopyOn_iff_cl, contract_ground, and_iff_left rfl, contract_cl_eq, empty_union, h.cl_eq]
State after:
no goals