| n < # buf1, ∀ buf1, buf0. n ≤ # buf1 → # buf1 = 0 ∨ datasize(buf1, n) = 0 ∨ datasize(buf0 + buf1, n + # buf0) = # buf0 + datasize(buf1, n) ∨ n = 0 ⊦ (buf1[n] = empty ⊃ datasize(buf0 + buf1, n + # buf0);(n + # buf0) + 1) = # buf0 + (buf1[n] = empty ⊃ datasize(buf1, n);n + 1), (buf1[n] = empty ⊃ datasize(buf1, n);n + 1) = 0 |
buf1[n] = empty, n < # buf1, ∀ buf1, buf0. n ≤ # buf1 → # buf1 = 0 ∨ datasize(buf1, n) = 0 ∨ datasize(buf0 + buf1, n + # buf0) = # buf0 + datasize(buf1, n) ∨ n = 0 ⊦ (buf1[n] = empty ⊃ datasize(buf1, n);n + 1) = 0, datasize(buf0 + buf1, n + # buf0) = # buf0 + (buf1[n] = empty ⊃ datasize(buf1, n);n + 1)
Used simplifier rules: ⊦ m + 1 ≠ 0; (s)%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)