Theorem: Matroid.girth_freeOn (Matroid/Circuit.lean)

State before:
α : Type u_1
M : Matroid α
C C' I X K C₁ C₂ R : Set α
e f x y : α
E D : Set α
⊢ (freeOn E).girth = ⊤
Tactic:
simp [Subset.rfl]
State after:
no goals