| n0 +1 ≤ # buf, ∀ buf. n0 ≤ # buf → datasize(buf, datasize(buf, n0)) = datasize(buf, n0) ⊦ datasize(buf, datasize(buf, n0 +1)) = datasize(buf, n0 +1) |
⊦ datasize(buf, n + 1) = (buf[n] = empty ⊃ datasize(buf, n);n + 1)
n0 < # buf, ∀ buf. n0 ≤ # buf → datasize(buf, datasize(buf, n0)) = datasize(buf, n0) ⊦ datasize(buf, (buf[n0] = empty ⊃ datasize(buf, n0);n0 + 1)) = (buf[n0] = empty ⊃ datasize(buf, n0);n0 + 1)
Used simplifier rules: datasize-rec: ⊦ datasize(buf, n + 1) = (buf[n] = empty ⊃ datasize(buf, n);n + 1);% ⊦ m < n → n ≠ 0; (s)%f: ⊦ m < n → n ≠ 0; (forward) from specification nat-basic% ⊦ m + 1 ≤ n ↔ m < n; (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)