| is-encoded(nd, subarray(buf, n + NODE_HEADER_SIZE, node-size-headerless(nd))), is-encoded(nodeheader(node-size-headerless(nd), false), subarray(buf, n, NODE_HEADER_SIZE)), range=(buf, n + NODE_HEADER_SIZE + align↑(node-size-headerless(nd), 2 * NODE_HEADER_SIZE), validtrailer, 0, NODE_HEADER_SIZE), (n + NODE_HEADER_SIZE) + node-size-headerless(nd) ≤ # buf, n + NODE_HEADER_SIZE ≤ # buf, n + align↑(node-size-headerless(nd), 2 * NODE_HEADER_SIZE) + 2 * NODE_HEADER_SIZE ≤ # buf ⊦ ∃ buf0, buf1. subarray(buf, n, 2 * NODE_HEADER_SIZE + align↑(node-size-headerless(nd), 2 * NODE_HEADER_SIZE)) = buf0 + buf1 + validtrailer ∧ is-encoded(nodeheader(node-size-headerless(nd), false), buf0) ∧ is-encoded(nd, subarray(buf1, 0, node-size-headerless(nd))) ∧ # buf1 = align↑(node-size-headerless(nd), 2 * NODE_HEADER_SIZE) |
⊦ n ≤ # buf → (∃ buf0, buf1. buf = buf0 + buf1 ∧ # buf0 = n)
is-encoded(nodeheader(node-size-headerless(nd), false), subarray(buf, n, NODE_HEADER_SIZE)), is-encoded(nd, subarray(buf, n + NODE_HEADER_SIZE, node-size-headerless(nd))), range=(buf, n + NODE_HEADER_SIZE + align↑(node-size-headerless(nd), 2 * NODE_HEADER_SIZE), validtrailer, 0, NODE_HEADER_SIZE), n + align↑(node-size-headerless(nd), 2 * NODE_HEADER_SIZE) + 2 * NODE_HEADER_SIZE ≤ # buf, n + NODE_HEADER_SIZE ≤ # buf, (n + NODE_HEADER_SIZE) + node-size-headerless(nd) ≤ # buf, n ≤ # buf → (∃ buf0, buf1. buf = buf0 + buf1 ∧ # buf0 = n) ⊦ ∃ buf0, buf1. subarray(buf, n, 2 * NODE_HEADER_SIZE + align↑(node-size-headerless(nd), 2 * NODE_HEADER_SIZE)) = buf0 + buf1 + validtrailer ∧ is-encoded(nodeheader(node-size-headerless(nd), false), buf0) ∧ is-encoded(nd, subarray(buf1, 0, node-size-headerless(nd))) ∧ # buf1 = align↑(node-size-headerless(nd), 2 * NODE_HEADER_SIZE)
Used terms: n, buf