Frame.untick: def of bolt@1.27.0.0
Import: import bolt@1.27.0.0/src/lsp/frame.bend as Frame
Lines 230-254 of bolt@1.27.0.0/src/lsp/frame.bend: https://jend.leeeet.dev/read.txt?path=bolt@1.27.0.0/src/lsp/frame.bend&start_line=230&end_line=254

import Base

# a count one less (zero stays zero)
def untick(ds: List<&2, Digit>) -> List<&2, Digit>:
  match ds:
    case Nil{}:
      Nil{}
    case Con{D0{}, t}:
      D9{} <> untick(t)
    case Con{D1{}, t}:
      D0{} <> t
    case Con{D2{}, t}:
      D1{} <> t
    case Con{D3{}, t}:
      D2{} <> t
    case Con{D4{}, t}:
      D3{} <> t
    case Con{D5{}, t}:
      D4{} <> t
    case Con{D6{}, t}:
      D5{} <> t
    case Con{D7{}, t}:
      D6{} <> t
    case Con{D8{}, t}:
      D7{} <> t
    case Con{D9{}, t}:
      D8{} <> t

Uses (2):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=List
  https://jend.leeeet.dev/definition.txt?path=bolt@1.27.0.0/src/lsp/frame.bend&name=Digit