def step_acc
import bend-collections@1.0.0.0/src/containers/doubly_linked_list.bend as DoublyLinkedListimport Base
import bend-collections@1.0.0.0/src/containers/types/doubly_linked_list.bend as E
359def step_acc(~T: Data, op: E.Op<T>, st: DList<T> & List<&2, E.Obs<T>>) -> DList<T> & List<&2, E.Obs<T>>:
360 (s, acc) = st
361 record(~T, acc, step(~T, s, op))