exact rew_eq_of_funEqOn₀ (by intro x hx; simp; rintro rfl; have := h p hp; contradiction)
case a
L : Language
Δ✝ Δ₁ Δ₂ Γ : Sequent L
p✝ q r : SyntacticFormula L
m : ℕ
Δ : Sequent L
h : ∀ p ∈ Δ, ¬fvar? p m
p : Semiformula L ℕ 0
hp : p ∈ Δ
⊢ (Rew.rewriteMap fun x => if x = m then 0 else x + 1).hom p = (Rew.hom ⇑) p
no goals