| # subarray(buf2, 0, n + NODE_HEADER_SIZE) = # subarray(buf0, 0, n + NODE_HEADER_SIZE), # buf = n1 + (n + NODE_HEADER_SIZE) + node-size-headerless(nd), # buf = n0 + n + 2 * NODE_HEADER_SIZE + nd.alignedsize, # buf0 = # buf, # buf2 = # buf, NODE_HEADER_SIZE + n0 + nd.alignedsize = node-size-headerless(nd) + n1, subarray(buf0, n + NODE_HEADER_SIZE, node-size-headerless(nd) + n1) = subarray(buf, n + NODE_HEADER_SIZE, node-size-headerless(nd) + n1), subarray(buf2, (n + NODE_HEADER_SIZE) + node-size-headerless(nd), n1) = subarray(buf0, (n + NODE_HEADER_SIZE) + node-size-headerless(nd), n1), n2 < n, is-encoded(nodeheader(node-size-headerless(nd), false), subarray(buf0, n, NODE_HEADER_SIZE)), n + 2 * NODE_HEADER_SIZE + nd.alignedsize ≤ # buf, n + NODE_HEADER_SIZE ≤ # buf, (n + NODE_HEADER_SIZE) + node-size-headerless(nd) ≤ # buf, ⌊err⌋ , ∀ n0. n0 < # subarray(buf2, 0, n + NODE_HEADER_SIZE) → subarray(buf2, 0, n + NODE_HEADER_SIZE)[n0] = subarray(buf0, 0, n + NODE_HEADER_SIZE)[n0] ⊦ buf2[n2] = buf0[n2] |
# buf2 = # buf, # buf0 = # buf, # buf = n0 + n + 2 * NODE_HEADER_SIZE + nd.alignedsize, # buf = n1 + (n + NODE_HEADER_SIZE) + node-size-headerless(nd), NODE_HEADER_SIZE + n0 + nd.alignedsize = node-size-headerless(nd) + n1, subarray(buf2, (n + NODE_HEADER_SIZE) + node-size-headerless(nd), n1) = subarray(buf0, (n + NODE_HEADER_SIZE) + node-size-headerless(nd), n1), subarray(buf0, n + NODE_HEADER_SIZE, node-size-headerless(nd) + n1) = subarray(buf, n + NODE_HEADER_SIZE, node-size-headerless(nd) + n1), n2 < n, is-encoded(nodeheader(node-size-headerless(nd), false), subarray(buf0, n, NODE_HEADER_SIZE)), (n + NODE_HEADER_SIZE) + node-size-headerless(nd) ≤ # buf, n + NODE_HEADER_SIZE ≤ # buf, n + 2 * NODE_HEADER_SIZE + nd.alignedsize ≤ # buf, ⌊err⌋ , ∀ n3. n3 < n + NODE_HEADER_SIZE → buf2[n3] = buf0[n3] ⊦ buf2[n2] = buf0[n2]
Used simplifier rules: ⊦ n + 0 = n; (s)% ⊦ n0 < n → subarray(buf, m, n)[n0] = buf[m + n0]; (s)%c: ⊦ m + n = n + m; from specification nat-basic%a: ⊦ (m + n0) + n1 = m + n0 + n1; from specification nat-basic% ⊦ m + n = m + n0 ↔ n = n0; (s)% ⊦ # subarray(buf, m, n) = n; (s)