| s ∩ s0 = ∅, s.max ∈ s, s.min ∈ s, s.min ∈ s0, s0.min ∈ s0, s0.max ∈ s0 ⊦ # s = 0, # s0 = 0, s = ∅, s0 = ∅, s.min < s0.min, s0.max < s.min |
⊦ s1 = s2 ↔ (∀ a. a ∈ s1 ↔ a ∈ s2)
s0.max ∈ s0, s0.min ∈ s0, s.min ∈ s0, s.min ∈ s, s.max ∈ s, ∀ a. a ∈ s ∩ s0 ↔ a ∈ ∅ ⊦ # s0 = 0, # s = 0, s = ∅, s0 = ∅, s0.max < s.min, s.min < s0.min
Used terms: ∅, s ∩ s0