anchor.diff:  c     
         do  i = 2-mbc, mx+mbc-1
   c     
  -c     # copy data along a slice into 1d arrays:
  +c        # copy data along a slice into 1d arrays:
            do m=1,meqn
               do j = 1-mbc, my+mbc
                  q1d(j,m) = qold(i,j,m)
  
positive.code:             end do
           end do
        end do
  c     
  c     
        return
        end
  
negative.code: c     
  c     #
  c     # update fluxes for use in AMR:
           do  m=1,meqn
              do  j=2-mbc,my+mbc
                 gm(i,j,m) = gm(i,j,m) + faddm(j,m)
  