| a ∈ s1, ∀ a0. ¬ a0 ∈ s1 ∨ ¬ a0 ∈ s0, ∀ s0. (∀ a. ¬ a ∈ s1 ∨ ¬ a ∈ s0) → #(s1 ∪ s0) = # s1 + # s0 ⊦ s1 = ∅, #(s0 ∪ s1) = # s1 + # s0, # s1 = 0 |
a ∈ s1, ∀ a0. ¬ a0 ∈ s1 ∨ ¬ a0 ∈ s0, (∀ a. ¬ a ∈ s1 ∨ ¬ a ∈ s0) → #(s1 ∪ s0) = # s1 + # s0 ⊦ s1 = ∅, #(s0 ∪ s1) = # s1 + # s0, # s1 = 0
Used terms: s0