intro p hp
α : Type u_1
Δ : Sequent α
T : Theory α
consisT : Consistent T
⊢ ∀ ⦃f : Formula α⦄,
    f ∈ maximalConsistentTheory consisT → { val := fun x => Formula.atom x ∈ maximalConsistentTheory consisT } ⊧ f
α : Type u_1
Δ : Sequent α
T : Theory α
consisT : Consistent T
p : Formula α
hp : p ∈ maximalConsistentTheory consisT
⊢ { val := fun x => Formula.atom x ∈ maximalConsistentTheory consisT } ⊧ p