| m0 +1 ≤ 1 + # x0, ∀ m, σ. m ≤ # x0 → ⌜x0⌝ + σ to m = ⌜x0 to m⌝ , ∀ x0, a, σ. m0 ≤ 1 + # x0 ∧ (∀ m, σ. m ≤ # x0 → ⌜x0⌝ + σ to m = ⌜x0 to m⌝ ) → (⌜a '⌝ + ⌜x0⌝ ) + σ to m0 = ⌜a ' + x0 to m0⌝ ⊦ (⌜a '⌝ + ⌜x0⌝ ) + σ to m0 +1 = ⌜a ' + x0 to m0 +1⌝ |
m0 ≤ # x0, ∀ x0, a, σ. m0 ≤ 1 + # x0 ∧ (∀ m, σ. m ≤ # x0 → ⌜x0⌝ + σ to m = ⌜x0 to m⌝ ) → (⌜a '⌝ + ⌜x0⌝ ) + σ to m0 = ⌜a ' + x0 to m0⌝ , ∀ m, σ. m ≤ # x0 → ⌜x0⌝ + σ to m = ⌜x0 to m⌝ ⊦ ⌜x0⌝ + σ to m0 = ⌜x0 to m0⌝
Used simplifier rules: to-succ-cons: ⊦ ⌜a '⌝ + σ to n + 1 = a + (σ to n);%cons-append: ⊦ a + σ = ⌜a '⌝ + σ;%append-assoc: ⊦ (σ + σ1) + σ2 = σ + σ1 + σ2;%to-succ-cons-l-lem: ⊦ a ' + x to n + 1 = a + (x to n);%append-finfin: ⊦ ⌜x + y⌝ = ⌜x⌝ + ⌜y⌝ ;%append-cancel-l: ⊦ ⌜x⌝ + σ0 = ⌜x⌝ + σ1 ↔ σ0 = σ1;% ⊦ m + n ≤ m + n0 ↔ n ≤ n0; (s)%a: ⊦ (x + y) + z = x + y + z; from specification list% ⊦ a + x = a ' + x; (s)%c: ⊦ m + n = n + m; from specification nat-basic%a: ⊦ (m + n0) + n1 = m + n0 + n1; from specification nat-basic% ⊦ m +1 = m + 1; (s)