anchor.diff:              if (iface_coarse .eq. 0) then
                  ic = ibc
               elseif (iface_coarse .eq. 1) then
  -               ic = mx + ibc - 1
  +               ic = mx - ibc + 1
               endif
               do jc = 1,mx
                  i1 = ic
  
positive.code:      &                       pv(4)*shiftx(m)*shifty(m)
                       qfine(iff,jff,mq) = qc + value
                    end do
                 endif
              enddo
              enddo
           else
              if (iface_coarse .eq. 2) then
                 jc = 1
              elseif (iface_coarse .eq. 3) then
                 jc = my
              endif
              do ic = 1,mx
      1          i1 = ic
  
negative.code:          ic = ibc
           jc = jbc
        elseif (icorner_coarse .eq. 1) then
           ic = mx - ibc + 1
           jc = jbc
        elseif (icorner_coarse .eq. 2) then
           ic = ibc
           jc = my - jbc+1
        elseif (icorner_coarse .eq. 3) then
           ic = mx - ibc+1
           jc = my - jbc+1
        endif
  
  c     # Interpolate coarse grid corners to fine grid corner ghost cells
  