ProofNum.FITSU: law of lawful-fields@0.1.1.0
Import: import lawful-fields@0.1.1.0/proof_num.bend as ProofNum
Lines 224-235 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=224&end_line=235

import Base

# num's test on words is the test on numbers (c the constant, q its value).
law FITSU:
  for +acc: U32
  for +x: U32
  for +c: U32
  for +q: Nat
  for +M: Nat
  for +hcq: {U32.to_nat(c) == q : Nat}
  for +hq: {Nat.add(Nat.mul(q, 10n), 6n) == M : Nat}
  for +hge: {U32.is_ge(x, 48) == True{} : Bool}
  for +hle: {U32.is_le(x, 57) == True{} : Bool}
  {Bool.or(U32.is_lt(acc, c), Bool.and(U32.is_eq(acc, c), U32.is_le(U32.sub(x, 48), 5))) == Nat.is_lt(Nat.add(Nat.mul(U32.to_nat(acc), 10n), Nat.sub(U32.to_nat(x), 48n)), M) : Bool}

Uses (24):
  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.or
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Equal.sym
  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.is_eq
  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.is_lt
  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.sub
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=U32
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=U32.is_eq
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=U32.is_ge
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=U32.is_le
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=U32.is_lt
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=U32.sub
  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/proof_num.bend&name=FITS0
  https://jend.leeeet.dev/definition.txt?path=lawful-fields@0.1.1.0/proof_num.bend&name=ed48
  https://jend.leeeet.dev/definition.txt?path=lawful-fields@0.1.1.0/proof_num.bend&name=k9
  https://jend.leeeet.dev/definition.txt?path=lawful-words@0.1.0.0/proof_u32.bend&name=is_eq_to_nat
  https://jend.leeeet.dev/definition.txt?path=lawful-words@0.1.0.0/proof_u32.bend&name=is_le_to_nat
  https://jend.leeeet.dev/definition.txt?path=lawful-words@0.1.0.0/proof_u32.bend&name=is_lt_to_nat