Defs.ok: def of lawful-bytes@0.1.1.0
Import: import lawful-bytes@0.1.1.0/defs.bend as Defs
Lines 37-43 of lawful-bytes@0.1.1.0/defs.bend: https://jend.leeeet.dev/read.txt?path=lawful-bytes@0.1.1.0/defs.bend&start_line=37&end_line=43

import Base
import lawful-arrays@0.1.0.0/defs.bend as A

# b is well formed with a block of depth d: a perfect block of 2^d words,
# d <= 29, and len within the block. A buffer holds at most 2^31 bytes (2 GiB),
# so every index and length fits in a U32; the laws' hypotheses keep sums of
# lengths in range too. Larger files are read in pieces.
def ok(b: Bytes, +d: Nat) -> Bool:
  Bytes{len, buf} = b
  A.full(U32, buf, d) && (Nat.is_le(d, 29n) && Nat.is_le(U32.to_nat(len), Nat.mul(4n, Nat.pow(2n, d))))

Uses (10):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Bool
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Bool.and
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Nat
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Nat.is_le
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Nat.mul
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Nat.pow
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=U32
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=U32.to_nat
  https://jend.leeeet.dev/definition.txt?path=lawful-arrays@0.1.0.0/defs.bend&name=full
  https://jend.leeeet.dev/definition.txt?path=lawful-bytes@0.1.1.0/defs.bend&name=Bytes