| 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) |
buf[n0] = empty, n0 < # buf, ∀ buf. n0 ≤ # buf → datasize(buf, datasize(buf, n0)) = datasize(buf, n0) ⊦ datasize(buf, datasize(buf, n0)) = (buf[n0] = empty ⊃ datasize(buf, n0);n0 + 1)
⊦ datasize(buf, n + 1) = (buf[n] = empty ⊃ datasize(buf, n);n + 1)
Used simplifier rules: datasize-rec: ⊦ datasize(buf, n + 1) = (buf[n] = empty ⊃ datasize(buf, n);n + 1);%a: ⊦ (m + n0) + n1 = m + n0 + n1; from specification nat-basic%c: ⊦ m + n = n + m; from specification nat-basic% ⊦ m + n = m + n0 ↔ n = n0; (s)