ProofFastW2.bt_bidx: law of lawful-bytes@0.1.1.0
Import: import lawful-bytes@0.1.1.0/proof_fast_w2.bend as ProofFastW2
Lines 336-342 of lawful-bytes@0.1.1.0/proof_fast_w2.bend: https://jend.leeeet.dev/read.txt?path=lawful-bytes@0.1.1.0/proof_fast_w2.bend&start_line=336&end_line=342

import Base
import lawful-bytes@0.1.1.0/fast.bend as FA

law bt_bidx:
  for +e0: Bool
  for +e1: Bool
  for +e2: Bool
  for +e3: Bool
  for +h: {Nat.is_lt(R4(e0, e1, e2, e3), 4n) == True{} : Bool}
  {U32.to_nat(U32.add(U32.add(FA.b2u(Bool.and(Bool.not(e0), True{})), FA.b2u(Bool.and(Bool.not(e0), Bool.and(Bool.not(e1), True{})))), FA.b2u(Bool.and(Bool.not(e0), Bool.and(Bool.not(e1), Bool.and(Bool.not(e2), True{})))))) == R4(e0, e1, e2, e3) : Nat}

Uses (11):
  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=Bool.not
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Empty.absurd
  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_lt
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=U32.add
  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/proof_base.bend&name=false_ne_true
  https://jend.leeeet.dev/definition.txt?path=lawful-bytes@0.1.1.0/fast.bend&name=b2u
  https://jend.leeeet.dev/definition.txt?path=lawful-bytes@0.1.1.0/proof_fast_w2.bend&name=R4