| ⊦ ⌜a '⌝ + ⌜nf⌝ = ⌜λ n. (n = 0 ⊃ a;nf(n - 1))⌝ |
⊦ ⌜nf⌝ = nf(0) + ⌜λ n. nf(n + 1)⌝
Used simplifier rules: cons-append: ⊦ a + σ = ⌜a '⌝ + σ;%append-cancel-l: ⊦ ⌜x⌝ + σ0 = ⌜x⌝ + σ1 ↔ σ0 = σ1;%append-assoc: ⊦ (σ + σ1) + σ2 = σ + σ1 + σ2;%oz: ⊦ m + 1 ≠ 0; from specification nat-basic2%a: ⊦ (m + n0) + n1 = m + n0 + n1; from specification nat-basic2%c: ⊦ m + n = n + m; from specification nat-basic2%add-01: ⊦ n ≤ m → m + n0 - n = (m - n) + n0; from specification nat%add-base: ⊦ n + 0 = n; from specification nat-basic2 Used terms: λ n. (n = 0 ⊃ a;nf(n - 1))