| max(sort(x0)) = max(x0), max(x0) < a ⊦ max(sort(x0) + a ') = a, x0 = [], ordered≤(sort(x0) + a ') |
⊦ ordered≤(x) ∧ ordered≤(x0) ∧ (x ≠ [] ∧ x0 ≠ [] → ¬ x0.head < x.last) → ordered≤(x + x0)
max(sort(x0)) = max(x0), max(x0) < a ⊦ max(sort(x0) + a ') = a, x0 = [], ordered≤(sort(x0) + a '), ordered≤(sort(x0)) ∧ ordered≤(a ') ∧ (sort(x0) ≠ [] ∧ a ' ≠ [] → ¬ a '.head < sort(x0).last)
Used terms: a ', sort(x0)