tauto
Δ : List Formula
F phi psi : 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 phi → Holds D I V E psi
no goals