case assume_ phi =>
  intro D I V E a1
  simp at a1
  exact a1
Δ : List Formula
F phi : Formula
⊢ ∀ (D : Type) (I : Interpretation D) (V : VarAssignment D) (E : Env),
    (∀ H ∈ [phi], Holds D I V E H) → Holds D I V E phi
no goals