induction p using rec' <;> simp[*, Rew.rel, Rew.nrel, fvarList, ←neg_eq]
L : Language
ξ : Type u_1
n n₁ n₂✝ n₂ m m₁ m₂ m₃ : ℕ
o : Type u_2
inst✝ : IsEmpty o
p : Semiformula L o n
⊢ (Rew.emb.hom p).fvarList = []
no goals