anchor.diff:    a(:,:) = b(lb1, lb2)
     sync all
     if (this_image() == 1) then
  -    caf(:,:)[this_image()] = b(lb1, lb2)
  +    caf(:,:)[num_images()] = b(lb1, lb2)
     end if
     sync all
     if (this_image() == num_images()) then
  
positive.code:                       = b(i:i_e:i_s*i_sgn1, j:j_e:j_s*i_sgn2)
                    sync all
                    if (this_image() == 1) then
                      caf(i:i_e:i_s*i_sgn1, j:j_e:j_s*i_sgn2)[1] &
                          = b(i:i_e:i_s*i_sgn1, j:j_e:j_s*i_sgn2)
                    end if
                    sync all
  
negative.code:                   a(i:i_e:i_s*i_sgn1, j:j_e:j_s*i_sgn2) = b(lb1, lb2)
                    sync all
                    if (this_image() == 1) then
                      caf(i:i_e:i_s*i_sgn1, j:j_e:j_s*i_sgn2)[num_images()] &
                          = b(lb1, lb2)
                    end if
                    sync all
  
  