| n = n0 +1, # x0 < n, ∀ n. # x0 ≤ n → x0 -p n = x0 ⊦ (a ' + x0) -p n = a ' + x0 |
# x0 ≤ n0, ∀ n. # x0 ≤ n → x0 -p n = x0 ⊦ x0 -p n0 = x0
Used simplifier rules: delpos-rec: ⊦ (a ' + x) -p (n + 1) = a + (x -p n);% ⊦ m < n ↔ ¬ n ≤ m; (ss)% ⊦ m < n + 1 ↔ ¬ n < m; (s)% ⊦ x + y = x + z ↔ y = z; (s)%a: ⊦ (x + y) + z = x + y + z; from specification list%c: ⊦ m + n = n + m; from specification nat-basic%a: ⊦ (m + n0) + n1 = m + n0 + n1; from specification nat-basic% ⊦ a + x = a ' + x; (s)% ⊦ m +1 = m + 1; (s)