| # buf0 = NODE_HEADER_SIZE, n < 2 * NODE_HEADER_SIZE + # buf1, is-aligned(n, NODE_HEADER_SIZE), is-aligned(# buf1, 2 * NODE_HEADER_SIZE), is-encoded(nodeheader(# buf1, true), buf0) ⊦ n = 0, # subarray(buf0 + buf1 + validtrailer, 0, n) ≥ NODE_HEADER_SIZE ∧ is-aligned(# subarray(buf0 + buf1 + validtrailer, 0, n), NODE_HEADER_SIZE) ∧ (∃ buf2, buf3. subarray(buf0 + buf1 + validtrailer, 0, n) = buf2 + buf3 ∧ # buf2 = NODE_HEADER_SIZE ∧ (is-garbage-header(buf2) ∨ (∃ ndhd. is-encoded(ndhd, buf2) ∧ # buf3 ≤ align↑(ndhd.size, 2 * NODE_HEADER_SIZE)))) |
# buf0 = NODE_HEADER_SIZE, n < 2 * NODE_HEADER_SIZE + # buf1, is-aligned(# buf1, 2 * NODE_HEADER_SIZE), is-aligned(n, NODE_HEADER_SIZE), is-encoded(nodeheader(# buf1, true), buf0) ⊦ n = 0, ∃ buf2, buf3. subarray(buf0 + buf1 + validtrailer, 0, n) = 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)% ⊦ n ≥ m ↔ m ≤ n; (s)% ⊦ # subarray(buf, m, n) = n; (s)