| # buf1 = nd.alignedsize, # buf0 = NODE_HEADER_SIZE, n < 2 * NODE_HEADER_SIZE + nd.alignedsize, is-aligned(n, NODE_HEADER_SIZE), is-encoded(nodeheader(node-size-headerless(nd), false), buf0), is-encoded(nd, subarray(buf1, 0, node-size-headerless(nd))), # buf0 ≤ n, n ≤ # buf0 + #(buf1 + validtrailer) ⊦ n = 0, ∃ buf2, buf3. buf0 + subarray(buf1 + validtrailer, 0, n - # buf0) = buf2 + buf3 ∧ # buf2 = NODE_HEADER_SIZE ∧ (is-garbage-header(buf2) ∨ (∃ ndhd. is-encoded(ndhd, buf2) ∧ # buf3 ≤ align↑(ndhd.size, 2 * NODE_HEADER_SIZE))) |
# buf1 = nd.alignedsize, # buf0 = NODE_HEADER_SIZE, n < 2 * NODE_HEADER_SIZE + nd.alignedsize, is-aligned(n, NODE_HEADER_SIZE), is-encoded(nodeheader(node-size-headerless(nd), false), buf0), is-encoded(nd, subarray(buf1, 0, node-size-headerless(nd))) ⊦ n = 0, ∃ buf2, buf3. buf0 + subarray(buf1 + validtrailer, 0, n - NODE_HEADER_SIZE) = buf2 + buf3 ∧ # buf2 = NODE_HEADER_SIZE ∧ (is-garbage-header(buf2) ∨ (∃ ndhd. is-encoded(ndhd, buf2) ∧ # buf3 ≤ align↑(ndhd.size, 2 * NODE_HEADER_SIZE)))
Used simplifier rules: m ≠ 0 ⊦ is-aligned(n, m) → (m ≤ n ↔ n ≠ 0); (s)% ⊦ NODE_HEADER_SIZE ≠ 0; (s)% ⊦ m < n → m ≤ n; (s)%m1 ≠ 0 ⊦ m ≤ (* m1) * m + n0; (s)% ⊦ m + m = 2 * m; (s)%c: ⊦ m + n = n + m; from specification nat-basic% ⊦ NODE_HEADER_SIZE + n ≠ 0; (s)%mult-c: ⊦ m * n = n * m; from specification nat-mult%mult-a: ⊦ m0 * m * n = (m0 * m) * n; from specification nat-mult% ⊦ m0 * 1 = m0; (s)%m1 ≠ 0 ⊦ m < (* m1) * m + n0 ↔ (m1 - 1) * m + n0 ≠ 0; (s)%let: ⊦ n ≤ n0 ∧ n0 ≤ n1 → n ≤ n1; (forward) from specification nat%fle-01: ⊦ m ≤ n ∧ n < n0 → m < n0; (forward) from specification nat%a: ⊦ (m + n0) + n1 = m + n0 + n1; from specification nat-basic%append-a: ⊦ (buf + buf0) + buf1 = buf + buf0 + buf1; from specification array-splice[buffer]% ⊦ # validtrailer = NODE_HEADER_SIZE; (s)% ⊦ #(buf + buf0) = # buf + # buf0; (s)