exact ⟨Or.inl X_in, satX⟩
case h
XS YS : List (List Formula)
W : Type
M : KripkeModel W
w : W
rhs : (¬∃ Y ∈ XS, ∀ f ∈ Y, evaluate M w f) → ∃ Y ∈ YS, ∀ f ∈ Y, evaluate M w f
X : List Formula
X_in : X ∈ XS
satX : ∀ f ∈ X, evaluate M w f
⊢ (X ∈ XS ∨ X ∈ YS) ∧ ∀ f ∈ X, evaluate M w f
no goals