anchor.diff:                          ifine = (ibc-1)*refratio + ii
                           jfine = (jbc-1)*refratio + jj
                           qf = qfine(ifine,my+1-jfine,mq)
  -                        kf = auxfine(ifine,my+1-jfine,mq)
  +                        kf = areafine(ifine,my+1-jfine)
                           sum = sum + kf*qf
                        enddo
                     enddo
  -                  kc = r2*auxcoarse(1-ibc,my+jbc,1)
  +                  kc = r2*areacoarse(1-ibc,my+jbc)
                     qcoarse(1-ibc,my+jbc,mq) = sum/r2
                  enddo
               enddo
  
positive.code: c     # to 'qcoarse' at face 'iside'  in direction 'idir' of 'qcoarse'
  c     # Assume this is mapped.
        subroutine mb_average_face_ghost(mx,my,mbc,meqn,qcoarse,
       &      qfine,auxcoarse, auxfine,
       &      idir,iface_coarse,p4est_refineFactor,refratio,igrid)
        implicit none
  
  
negative.code:                         ifine = (ibc-1)*refratio + ii
                          jfine = (jbc-1)*refratio + jj
                          qf = qfine(mx+1-ifine,jfine,mq)
                          kf = areafine(mx+1-ifine,jfine)
                          sum = sum + kf*qf
                       enddo
                    enddo
                    kc = r2*areacoarse(mx+ibc,1-jbc)
                    qcoarse(mx+ibc,1-jbc,mq) = sum/r2
                 enddo
              enddo
  