| #(s ∪ s0) ≤ # s ⊦ #(s ∪ s0) = # s, #(s ∪ s0) < # s, ∀ a. a ∈ s0 → a ∈ s |
⊦ m ≠ n → (m < n ↔ ¬ n < m)
Used simplifier rules: union-sizeeq: ⊦ #(s ∪ s0) = # s ↔ s0 ⊆ s;%una: ⊦ (s ∪ s0) ∪ s1 = s ∪ s0 ∪ s1;%unc: ⊦ s ∪ s0 = s0 ∪ s;% ⊦ s1 ⊆ s2 ↔ (∀ a. a ∈ s1 → a ∈ s2); (s)%ne-01: ⊦ a ∈ s → s ≠ ∅; (forward) from specification set-basic%f: ⊦ m < n → n ≠ 0; (forward) from specification nat-basic%fle: ⊦ m < n ∧ n ≤ n0 → m < n0; (forward) from specification nat%fle-01: ⊦ m ≤ n ∧ n < n0 → m < n0; (forward) from specification nat% ⊦ s1 = s2 ↔ (∀ a. a ∈ s1 ↔ a ∈ s2); (s)% ⊦ ¬ a ∈ ∅; (s)% ⊦ m < n → n ≠ 0; (s)% ⊦ ¬ n < n; (s) Used terms: # s, #(s ∪ s0)