case box α φ =>
  have IHα := repl_in_model_rel_iff x ψ α M w
  simp [evaluatePoint, modelCanSemImplyForm] at *
  constructor
  all_goals
    intro hyp v rel
    have IHφ := repl_in_model_sat_iff x ψ φ M v
    specialize IHα v
    specialize hyp v
    tauto
x : ℕ
ψ : Formula
W : Type
M : KripkeModel W
w : W
α : Program
φ : Formula
⊢ (M, w)⊨repl_in_F x ψ (⌈α⌉φ) ↔ (repl_in_model x ψ M, w)⊨⌈α⌉φ
no goals