| ordered≤(x1), x ⊒ a ' + x1, ∀ x0. x0 ⊒ x1 → ordered≤(x0) ⊦ x1 = [], x1.head < a, ordered≤(x) |
x1 = a0 + y, ordered≤(x1), x ⊒ a ' + x1, ∀ x0. x0 ⊒ x1 → ordered≤(x0) ⊦ x1 = [], a0 < a, ordered≤(x)
Used simplifier rules: x ≠ [] ⊦ a = x.head ∧ y = x.tail ↔ x = a + y; (elim) Used terms: x1, a0, y