| #(s0 ++ a0) = 1, a ∈ s0, ∀ a, b. # s0 = 1 ∧ a ∈ s0 ∧ b ∈ s0 → a = b, b = a0 ∨ b ∈ s0 ⊦ a = b |
#(s0 ++ a0) = 1, a ∈ s0, a0 ∈ s0, ∀ a, b. # s0 = 1 ∧ a ∈ s0 ∧ b ∈ s0 → a = b, b = a0 ∨ b ∈ s0 ⊦ a = b
#(s0 ++ a0) = 1, a ∈ s0, ∀ a, b. # s0 = 1 ∧ a ∈ s0 ∧ b ∈ s0 → a = b, b = a0 ∨ b ∈ s0 ⊦ a = b, a0 ∈ s0
Used formulas: a0 ∈ s0