anchor.diff:  !=======+=========+=========+=========+=========+=========+=========+=========+
   
   logical function is_in_this_polygon(x, y, polygon, is_lat_lon)
  -  use jcf_sphere_lib, only : is_inner
  +  use jcf_spherical_lib, only : is_inner
     implicit none
     real(kind=8), intent(IN) :: x, y
     type(polygon_type), intent(IN) :: polygon
  
positive.code:     y1 = current_polygon%point(i1)%ptr%y
      x2 = current_polygon%point(i2)%ptr%x
      y2 = current_polygon%point(i2)%ptr%y
      if (is_cross_line(ys, xs, ye, xe, y1, x1, y2, x2, y, x)) then
        next_polygon => current_polygon%next_polygon(i1)%ptr
        return
      end if
  
negative.code:   type(polygon_type), pointer :: next_polygon
    real(kind=8) :: x1, y1, x2, y2
    integer :: i1, i2
    logical :: do_intersect
  
    do i1 = 1, current_polygon%num_of_point
      i2 = mod(i1, current_polygon%num_of_point) + 1
  