| a ∈ s ⊦ # s = 0, st[a, d][b] = st[b], s = ∅, b ∈ s |
a ∈ s0 ++ a0, ∀ a, st, d, b. a ∈ s0 → # s0 = 0 ∨ st[a, d][b] = st[b] ∨ s0 = ∅ ∨ b ∈ s0 ⊦ #(s0 ++ a0) = 0, s0 ++ a0 = ∅, st[a, d][b] = st[b], b ∈ s0 ++ a0
Used simplifier rules: set generated by ∅, ++;;