proofs/containers/doubly_linked_list/step.bend checks

import Base
import ../../lib/logic.bend as L
import ../../lib/nat.bend as N
import ../../lib/u32alg.bend as A
import ../../lib/array.bend as AR
import ../../lib/list.bend as LL
import ../../../spec/lib/common.bend as SC
import ../../../spec/containers/doubly_linked_list.bend as S
import ../../lib/u32div.bend as UD
import ../../../src/containers/doubly_linked_list.bend as D
import ../../../src/containers/internal/dlist_storage.bend as R
import ../../../src/containers/types/doubly_linked_list.bend as E
import ./state.bend as ST
import ./vals.bend as VA
import ./ok.bend as OK
import ./insp.bend as IP
import ./ins.bend as IN
import ./valid.bend as VD
import ./hrd.bend as HR
import ./hnb.bend as NB
import ./hlive.bend as HL
import ./hins.bend as HI
import ./walk.bend as WL
import ../../lib/nat_list.bend as NL
import ../../lib/links.bend as LK