| ∀ n, y. n ≤ # y → lastn(n, x0 + y) = lastn(n, y), n ≤ # y ⊦ lastn(n, (a + x0) + y) = lastn(n, y) |
n ≤ # y, ∀ n, y. n ≤ # y → lastn(n, x0 + y) = lastn(n, y) ⊦ lastn(n, (a ' + x0) + y) = lastn(n, y)
Used simplifier rules: a: ⊦ (x + y) + z = x + y + z; from specification list%c: ⊦ a + x = a ' + x; from specification list