| a ∈ s1 ⊦ # s1 = 0, ((s0 ++ a) ∩ s1) -- a = s0 ∩ s1, s1 = ∅, (s0 ++ a) ∩ s1 = s0 ∩ s1, a ∈ s0 |
⊦ s1 = s2 ↔ (∀ a. a ∈ s1 ↔ a ∈ s2)
Used simplifier rules: Delete: ⊦ a ∈ s -- b ↔ a ≠ b ∧ a ∈ s;%Intersect: ⊦ a ∈ s1 ∩ s2 ↔ a ∈ s1 ∧ a ∈ s2;%int-a: ⊦ (s ∩ s0) ∩ s1 = s ∩ s0 ∩ s1;%int-c: ⊦ s ∩ s0 = s0 ∩ s;% ⊦ a ∈ s ++ b ↔ a = b ∨ a ∈ s; (s) Used terms: s0 ∩ s1, ((s0 ++ a) ∩ s1) -- a