def obs_nat
import bend-collections@1.0.0.0/src/containers/bitlist.bend as Bitlistimport Base
import bend-collections@1.0.0.0/src/containers/types/bitlist.bend as E
280def obs_nat(r: Bitlist & Nat) -> Bitlist & E.Obs:
281 (s, x) = r
282 (s, E.ONat{x})