ProofNum.inv_step: law of lawful-fields@0.1.1.0
Import: import lawful-fields@0.1.1.0/proof_num.bend as ProofNum
Lines 417-428 of lawful-fields@0.1.1.0/proof_num.bend: https://jend.leeeet.dev/read.txt?path=lawful-fields@0.1.1.0/proof_num.bend&start_line=417&end_line=428

import Base
import lawful-fields@0.1.1.0/defs.bend as F

law inv_step:
  for +ok: Bool
  for +acc: U32
  for +m: Maybe<&2, Nat>
  for +x: U32
  for +M: Nat
  for +q: Nat
  for +hm: {Nat.pow(2n, 32n) == M : Nat}
  for +hcq: {U32.to_nat(429496729) == q : Nat}
  for +hq: {Nat.add(Nat.mul(q, 10n), 6n) == M : Nat}
  for +hi: Inv(ok, acc, m, M)
  Inv(Bool.and(ok, Bool.and(DG(x), FT(acc, x))), NA(acc, x), F.dec.push(m, F.digit(x)), M)

Uses (19):
  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=Equal.sym
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Maybe
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Nat
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Nat.add
  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=Sigma
  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-fields@0.1.1.0/defs.bend&name=dec.push
  https://jend.leeeet.dev/definition.txt?path=lawful-fields@0.1.1.0/defs.bend&name=digit
  https://jend.leeeet.dev/definition.txt?path=lawful-fields@0.1.1.0/proof_num.bend&name=DG
  https://jend.leeeet.dev/definition.txt?path=lawful-fields@0.1.1.0/proof_num.bend&name=FT
  https://jend.leeeet.dev/definition.txt?path=lawful-fields@0.1.1.0/proof_num.bend&name=Inv
  https://jend.leeeet.dev/definition.txt?path=lawful-fields@0.1.1.0/proof_num.bend&name=NA
  https://jend.leeeet.dev/definition.txt?path=lawful-fields@0.1.1.0/proof_num.bend&name=bad_step
  https://jend.leeeet.dev/definition.txt?path=lawful-fields@0.1.1.0/proof_num.bend&name=step_dg