def obs_nat
import bend-collections@1.0.0.0/src/containers/internal/dlist_storage.bend as DlistStorageimport Base
import bend-collections@1.0.0.0/src/containers/types/internal_dlist.bend as E
454def obs_nat(~T: Data, r: DList<T> & Nat) -> DList<T> & E.Obs<T>:
455 (s, n) = r
456 (s, E.ONat{n})