| a ∈ s, ∀ a. ¬ a ∈ s ∨ ¬ a ∈ s0, ∀ a. ¬ a ∈ s ∨ ¬ a ∈ s1, a ∈ s0 ∨ a ∈ s1 ⊦ # s = 0, s = ∅ |
a ∈ s, a ∈ s0, ∀ a. ¬ a ∈ s ∨ ¬ a ∈ s1, ∀ a. ¬ a ∈ s ∨ ¬ a ∈ s0 ⊦ # s = 0, s = ∅
a ∈ s, a ∈ s1, ∀ a. ¬ a ∈ s ∨ ¬ a ∈ s1, ∀ a. ¬ a ∈ s ∨ ¬ a ∈ s0 ⊦ # s = 0, s = ∅