is_emptyniltrueis_emptyconsxlfalsehdconsxlxtlconsxllappendl1l2ifappendl1l2l1ifappendl1l2nill2ifappendl1l2consxlconsxappendll22.1appendl1l2ifappendl1l2l1ifappendl1l2consxlappendll2truecons20cons22ifappendl1l2consxlappendll23true12false2appendl1l2ifappendl1l2l11false12false21false3
AProVE
3d3b40ebf1f1cc0cfb76e51606fb79299fd7ea19 rene 20120105 unpublished dirty
http://aprove.informatik.rwth-aachen.de/
John
Doe