Theorem: LO.FirstOrder.Rew.substs_comp_substs (Logic/FirstOrder/Basic/Syntax/Rew.lean)

State before:
L : Language
L' : Language
L₁ : Language
L₂ : Language
L₃ : Language
ξ : Type u_1
ξ' : Type u_2
ξ₁ : Type u_3
ξ₂ : Type u_4
ξ₃ : Type u_5
n n₁ n₂ n₃ : ℕ
ω : Rew L ξ₁ n₁ ξ₂ n₂
n' : ℕ
w✝ : Fin n → Semiterm L ξ n'
l k : ℕ
v : Fin l → Semiterm L ξ k
w : Fin k → Semiterm L ξ n
⊢ (substs w).comp (substs v) = substs (⇑(substs w) ∘ v)
Tactic:
ext <;> simp[comp_app]
State after:
no goals