| ∀ m, n. m + n ≤ # x0 → lastn(m, restn(n, x0)) = lastn(m, x0), m + n ≤ #(a + x0) ⊦ lastn(m, restn(n, a + x0)) = lastn(m, a + x0) |
m + n ≤ # x0 + 1, ∀ m, n. m + n ≤ # x0 → lastn(m, restn(n, x0)) = lastn(m, x0) ⊦ lastn(m, restn(n, a ' + x0)) = lastn(m, a ' + x0)
Used simplifier rules: a: ⊦ (x + y) + z = x + y + z; from specification list%succ: ⊦ m +1 = m + 1; from specification nat-basic2%len-05: ⊦ #(a ' + x) = (# x)+1; from specification list%c: ⊦ a + x = a ' + x; from specification list