anchor.diff:          enddo
        enddo
   
  -     do j = jlo-1, jhi+2
  +     do j = jlo-2, jhi+3
           do i = ilo, ihi
              ! these live on cell-centers
              dafm(i,j) = a(i,j) - a_int(i,j)
  
positive.code: 
             ! these live on cell-centers
             d2af(i,j) = 6.0*(a_int(i,j) - 2.0*a(i,j) + a_int(i,j+1))
             d2ac(i,j) = a(i,j-1) - 2.0*a(i,j) + a(i,j+1)
  
             ! this lives on the interface
             d3a(i,j) = d2ac(i,j) - d2ac(i,j-1)
  
          enddo
       enddo
  
  
negative.code:      enddo
  
       do j = jlo, jhi
          do i = ilo-2, ihi+3
             ! these live on cell-centers
             dafm(i,j) = a(i,j) - a_int(i,j)
             dafp(i,j) = a_int(i+1,j) - a(i,j)
  
             ! these live on cell-centers
             d2af(i,j) = 6.0*(a_int(i,j) - 2.0*a(i,j) + a_int(i+1,j))
          enddo
       enddo
  
       do j = jlo, jhi
          do i = ilo-3, ihi+3
             d2ac(i,j) = a(i-1,j) - 2.0*a(i,j) + a(i+1,j)
          enddo
       enddo
  
       do j = jlo, jhi
          do i = ilo-2, ihi+3
             ! this lives on the interface
             d3a(i,j) = d2ac(i,j) - d2ac(i-1,j)
          enddo
       enddo
  
  