12.0.13 `print_xdvi_form'
-------------------------

print_xdvi_form(S)
     :  It transforms S to a xdvi file and previews the file by xdvi.
Example 0:
      print_xdvi_form(newmat(2,2,[[x^2,x],[y^2-1,x/(x-1)]]));
   Example 1:
      print_xdvi_form(print_tex_form(1/2));

   References:

      `print_tex_form' ,  `print_dvi_form'

