| n0 ≠ 0, # x0 + 1 = n0 + n, ∀ n0, n. # x0 = n0 + n → firstn(n0, x0) + restn(n0, x0) = x0 ⊦ (a ' + firstn(n0 -1, x0)) + restn(n0, a ' + x0) = a ' + x0 |
# x0 + 1 = n0 + n, ∀ n0, n. # x0 = n0 + n → firstn(n0, x0) + restn(n0, x0) = x0 ⊦ n0 = 0, firstn(n0 - 1, x0) + restn(n0, a ' + x0) = x0
Used simplifier rules: app-08: ⊦ a ' + x = a ' + y ↔ x = y; from specification list%a: ⊦ (x + y) + z = x + y + z; from specification list%pred-03: ⊦ n -1 = n - 1; from specification nat