Role.roots: def of bolt@1.27.0.0
Import: import bolt@1.27.0.0/src/role.bend as Role
Lines 117-124 of bolt@1.27.0.0/src/role.bend: https://jend.leeeet.dev/read.txt?path=bolt@1.27.0.0/src/role.bend&start_line=117&end_line=124

import Base

# the roots of the laws: every LAWS.bend and PROOF.bend
def roots(fs: List<&2, Fact>) -> List<&2, String>:
  match fs:
    case Nil{}:
      Nil{}
    case Con{Fact{norm, _deps, +named, _entry}, rest}:
      +more = roots(rest)
      Bool.pick(List<&2, String>, is_law_file(named), norm <> more, more)

Uses (5):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Bool.pick
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=List
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=String
  https://jend.leeeet.dev/definition.txt?path=bolt@1.27.0.0/src/role.bend&name=Fact
  https://jend.leeeet.dev/definition.txt?path=bolt@1.27.0.0/src/role.bend&name=is_law_file