case inl v_α_w =>
  have v_Fℓα : evaluate M v (Con (F α ℓ)) := by simp_all [conEval, F, modelCanSemImplyForm, evaluatePoint]
  have IHα := existsBoxFP α v_α_w ℓ v_Fℓα rcases IHα with ⟨δ, _⟩
  use δ
  simp_all [P]
W✝ : Type
M : KripkeModel W✝
v w : W✝
α β : Program
ℓ : TP (α⋓β)
v_conF : (M, v)⊨Con (F (α⋓β) ℓ)
v_α_w : relate M α v w
⊢ ∃ δ ∈ P (α⋓β) ℓ, relateSeq M δ v w
no goals