case inl h₂ =>
  have ⟨v₁, hv₁⟩ := h₁ 
  have ⟨v₂, hv₂⟩ := h₂
  subst hv₁ hv₂
  have ⟨body₁, hv₁⟩ := canonical_forms ht₁
  subst hv₁
  exact ⟨_, .beta ..⟩
t : Term
ty : Ty
ctx : Ctx
t₁✝ : Term
ty₁ ty₂✝ : Ty
t₂✝ : Term
ht₁ : ∅ ⊢ t₁✝ ⋮ Ty.arrow ty₁ ty₂✝
a✝ : ∅ ⊢ t₂✝ ⋮ ty₁
h₁ : ∃ v, t₁✝ = Term.abs v.1 v.2
h₂ : ∃ v, t₂✝ = Term.abs v.1 v.2
⊢ ∃ t', Term.app t₁✝ t₂✝ ⇒ t'
no goals