| x3 + x ≠ [], max(x3 + a0 ' + x) = max((a0 ' + x) + x3), max(x + a ' + x3) = (max(x3 + x) < a ⊃ a;max(x3 + x)), ∀ x1, x2. # x1 + # x2 < #(a + x3) + #(a0 + x) → true → x1 + x2 = [] ∨ max(x1 + x2) = max(x2 + x1) ⊦ (max((a0 ' + x) + x3) < a ⊃ a;max((a0 ' + x) + x3)) = ((max(x3 + x) < a ⊃ a;max(x3 + x)) < a0 ⊃ a0;(max(x3 + x) < a ⊃ a;max(x3 + x))) |
max(x3 + a0 ' + x) = max((a0 ' + x) + x3), max(x + a ' + x3) = (max(x3 + x) < a ⊃ a;max(x3 + x)), ∀ x1, x2. # x1 + # x2 < #(a + x3) + #(a0 + x) → true → x1 + x2 = [] ∨ max(x1 + x2) = max(x2 + x1) ⊦ (max((a0 ' + x) + x3) < a ⊃ a;max((a0 ' + x) + x3)) = ((max(x3 + x) < a ⊃ a;max(x3 + x)) < a0 ⊃ a0;(max(x3 + x) < a ⊃ a;max(x3 + x))), x3 + x = []