| n ≤ # x0 + 1, n -1 ≤ # x0 → (∃ y, z. x0 = y + z ∧ # y = n -1) ⊦ ∃ y, z. a ' + x0 = y + z ∧ # y = n |
n ≤ # x0 + 1, n - 1 ≤ # x0 → x0 = y + z ∧ # y = n - 1 ⊦ ∃ y, z. a ' + x0 = y + z ∧ # y = n
Used simplifier rules: pred-03: ⊦ n -1 = n - 1; from specification nat