simp only [Holds]
Δ : List Formula
F phi psi chi : Formula
D : Type
I : Interpretation D
V : VarAssignment D
E : Env
a✝ : ∀ H ∈ [], Holds D I V E H
⊢ Holds D I V E ((phi.imp_ (psi.imp_ chi)).imp_ ((phi.imp_ psi).imp_ (phi.imp_ chi)))
Δ : List Formula
F phi psi chi : Formula
D : Type
I : Interpretation D
V : VarAssignment D
E : Env
a✝ : ∀ H ∈ [], Holds D I V E H
⊢ (Holds D I V E phi → Holds D I V E psi → Holds D I V E chi) →
    (Holds D I V E phi → Holds D I V E psi) → Holds D I V E phi → Holds D I V E chi