Bits.go_acc: def of bend-collections-laws-math@1.0.0.0
Import: import bend-collections-laws-math@1.0.0.0/proofs/math/natural/bits.bend as Bits
Lines 43-50 of bend-collections-laws-math@1.0.0.0/proofs/math/natural/bits.bend: https://jend.leeeet.dev/read.txt?path=bend-collections-laws-math@1.0.0.0/proofs/math/natural/bits.bend&start_line=43&end_line=50

import Base
import bend-collections-laws-math@1.0.0.0/src/math/natural.bend as M

def go_acc(fuel: Nat, +n: Nat, +k: Nat) -> {M.bit_length_go(fuel, n, 1n+k) == 1n+M.bit_length_go(fuel, n, k) : Nat}:
  match fuel n:
    case 0n n0:
      {==}
    case 1n+f 0n:
      {==}
    case 1n+ +f 1n+ +np:
      go_acc(f, Nat.div(1n+np, 2n), 1n+k)

Uses (3):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Nat
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Nat.div
  https://jend.leeeet.dev/definition.txt?path=bend-collections-laws-math@1.0.0.0/src/math/natural.bend&name=bit_length_go