| a ∈ s, ∀ a. a ∈ s → a ∈ s0, ∀ a. a ∈ s1 → a ∈ s2, ∀ a. a ∈ s3 → a ∈ s4 ⊦ a ∈ s4, a ∈ s2, a ∈ s0 |
a ∈ s, a0 ∈ s, ∀ a. a ∈ s → a ∈ s0, ∀ a. a ∈ s1 → a ∈ s2, ∀ a. a ∈ s3 → a ∈ s4 ⊦ a ∈ s4, a ∈ s2, a ∈ s0
Used simplifier rules: ⊦ ¬ a ∈ ∅; (s)% ⊦ s1 = s2 ↔ (∀ a. a ∈ s1 ↔ a ∈ s2); (s)%ne-01: ⊦ a ∈ s → s ≠ ∅; (forward) from specification set-basic