| m < n ⊦ (x to n)[m] = x[m], # x < n |
m < n, m < # x, n ≤ # x ⊦ (x to n)[m] = x[m], x = []
Used simplifier rules: ⊦ # x = 0 ↔ x = []; (s)% ⊦ m < n → n ≠ 0; (s)%fle: ⊦ m < n ∧ n ≤ n0 → m < n0; (forward) from specification nat%f: ⊦ m < n → n ≠ 0; (forward) from specification nat-basic% ⊦ m < n ↔ ¬ n ≤ m; (ss)