Theorem: LO.FirstOrder.Semiformula.fvarList_neg (Logic/FirstOrder/Basic/Syntax/Formula.lean)

State before:
L : Language
ξ : Type u_1
n n₁ n₂✝ n₂ m m₁ m₂ m₃ : ℕ
p : Semiformula L ξ n
⊢ (~p).fvarList = p.fvarList
Tactic:
induction p using rec' <;> simp[*, fvarList, ←neg_eq]
State after:
no goals