anchor.diff:        write(lout,"(a)")    "APER> ...no need to insert an upstream marker - no shift of downstream entries required."
       end if
     end if
  +#ifdef DEBUG
  +  write(lout,*) "check 01: il, iu, iuold, iElUp, iElDw, ic(iElUp)-nblo, ic(iElDw)-nblo", & 
  +       il, iu, iuold, iElUp, iElDw, ic(iElUp)-nblo, ic(iElDw)-nblo
  +  call dumpMe
  +#endif
   
   ! downstream marker
     iuold=iu
     call contour_aperture_marker( iElDw, .false. )
   ! the addition of the downstream aperture marker may have shifted by one the downstream entries
     if( iu-iuold.ne.0 ) then
  -! NB: if lAccrossLatticeExtremes, the downstream marker is almost at the beginngin of
  +! NB: if lAccrossLatticeExtremes, the downstream marker is almost at the beginning of
   !     the lattice structure! Hence, if a new entry has been inserted,
   !     the upstream marker (towards the end of the lattice structure) is
   !     shifted by 1
  
positive.code:   do i=1,iu
      ix=ic(i)-nblo
      if( ix.gt.0 ) then
        write(lout,"(a,i8,1x,a,1x,f15.6,1x,i8)") "APER> ",i,bez(ix),dcum(i),kape(ix)
      else
        write(lout,"(a,i8,1x,a,1x,f15.6)") "APER> ",i,bezb(ic(i)),dcum(i)
      end if
    end do
    write(lout,"(a)") "APER> dumpMe -----------------------------------------------------------------------------"
  
negative.code:   iElDw=itElDw
  ! markers accross extremes of lattice structure?
    lAccrossLatticeExtremes=iElUp.gt.iElDw
  #ifdef DEBUG
    write(lout,*) "check 00: il, iu, iuold, iElUp, iElDw, ic(iElUp)-nblo, ic(iElDw)-nblo", & 
         il, iu, iuold, iElUp, iElDw, ic(iElUp)-nblo, ic(iElDw)-nblo
    call dumpMe
  #endif
  
  ! upstream marker
    iuold=iu
  