anchor.diff:        double precision efneighbor3(mx,meqn,0:1)
   
   
  -      double precision delta, deltap, deltam, areathis
  +      double precision delta, deltap, deltam, area
   
         double precision neighborval
   
         integer*8 transform_cptr
   
   
  -      integer i,j,ibc,jbc,mq
  +      integer i,j,mq
         integer i1,j1, i2, j2
   
         idir = this_iface/2
  
positive.code: c           # NOTE : Fluxes have already been scaled by gamma, e.g. 
  c           # x-face-length/dy or y-face-length/dx
  
              fp_left(j,m) = fp_left(j,m) - dt*dy*fp(1,j,m)
              fm_left(j,m) = fm_left(j,m) + dt*dy*fm(1,j,m)
  
              fp_right(j,m) = fp_right(j,m)-dt*dy*fp(mx+1,j,m)
              fm_right(j,m) = fm_right(j,m)+dt*dy*fm(mx+1,j,m)
  
negative.code:                   if (this_iface .eq. 0) then
                       delta = neighborval  + fpthis0(j1,mq) 
       &                             - efthis0(j1,mq,0)
                       area = area0(j1)
  
                       write(6,100) this_iface, j1, neighborval, 
       &                       fpthis0(j1,mq), 
       &                       efthis0(j1,mq,0), delta
  
  
                       fpthis0(j1,mq) = 0
                       efthis0(j1,mq,0) = 0
  c                     efthis0(j1,mq,0) = 0
                    else
  c                   # Coarse grid is left; fine grid is right                    
  c                    # efc1(0) is flux stored in the coarse grid 
  c                    # interior cell. 
                       delta = neighborval + fmthis1(j1,mq) + 
       &                             efthis1(j1,mq,0)
                       area = area1(j1)
  
                       write(6,100) this_iface, j1, neighborval, 
       &                       fmthis1(j1,mq), 
       &                       efthis1(j1,mq,0), delta
  100                  format(2I5, 4F24.16)
  
  c                    # Reset these, since they will no longer be needed                     
                       fmthis1(j1,mq) = 0
                       efthis1(j1,mq,0) = 0
  c                     efthis1(j1,mq,1) = 0
                    endif
                    qthis(i1,j1,mq) = qthis(i1,j1,mq) + 0.5*delta/area
                enddo
            enddo
        else
            do mq = 1,meqn
                do i = 1,mx
  c                 # Exchange at high side of 'this' grid in
  c                 # y-direction (idir == 1)
                    i1 = i
  