intro φ' is_in
case h
X : Finset Formula
φ : Formula
W : Type
M : KripkeModel W
w : W
satX : ∀ φ_1 ∈ X ∪ {~~φ}, Evaluate (M, w) φ_1
⊢ ∀ φ_1 ∈ X ∪ {φ}, Evaluate (M, w) φ_1
case h
X : Finset Formula
φ : Formula
W : Type
M : KripkeModel W
w : W
satX : ∀ φ_1 ∈ X ∪ {~~φ}, Evaluate (M, w) φ_1
φ' : Formula
is_in : φ' ∈ X ∪ {φ}
⊢ Evaluate (M, w) φ'