def record
import bend-collections@1.0.0.0/src/containers/bitset.bend as Bitsetimport Base
import bend-collections@1.0.0.0/src/containers/types/bitset.bend as E
536def record(acc: List<&2, E.Obs>, r: Bitset & E.Obs) -> Bitset & List<&2, E.Obs>:
537 (s, o) = r
538 (s, Con{o, acc})