Bigint.Mag.dec: def of bend-kit-bignum@0.1.0.0
Import: import bend-kit-bignum@0.1.0.0/bigint.bend as Bigint
Lines 78-88 of bend-kit-bignum@0.1.0.0/bigint.bend: https://jend.leeeet.dev/read.txt?path=bend-kit-bignum@0.1.0.0/bigint.bend&start_line=78&end_line=88

import Base

# a - w for the borrow w; z says w is 0. Leaves zero limbs on top.
def Mag.dec(a: List<&2, U32>, z: Bool, +w: U32) -> List<&2, U32>:
  match a z:
    case s True{}:
      s
    case Nil{} False{}:
      Nil{}
    case Con{x, xs} False{}:
      +t = (x + 10000 - w : U32)
      +k = (1 - t / 10000 : U32)
      Con{(t % 10000 : U32), Mag.dec(xs, U32.is_zero(k), k)}

Uses (8):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Bool
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=List
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=U32
  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.div
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=U32.is_zero
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=U32.mod
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=U32.sub