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