Theorem: Matroid.Indep.of_minor (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 : Set α
M₀ M₁ M₂ : Matroid α
hI : N.Indep I
hNM : N ≤m M
⊢ M.Indep I
Tactic:
obtain ⟨C,D, rfl⟩ := minor_iff_exists_contract_delete.1 hNM
State after:
case intro.intro
α : Type u_1
M M' : Matroid α
e f : α
I J R B X Y Z K : Set α
M₀ M₁ M₂ : Matroid α
C D : Set α
hI : (M ／ C ＼ D).Indep I
hNM : M ／ C ＼ D ≤m M
⊢ M.Indep I

State before:
case intro.intro
α : Type u_1
M M' : Matroid α
e f : α
I J R B X Y Z K : Set α
M₀ M₁ M₂ : Matroid α
C D : Set α
hI : (M ／ C ＼ D).Indep I
hNM : M ／ C ＼ D ≤m M
⊢ M.Indep I
Tactic:
exact hI.of_delete.of_contract
State after:
no goals