Welcome to SWI-Prolog (Multi-threaded, 64 bits, Version 6.6.5)
Copyright (c) 1990-2013 University of Amsterdam, VU Amsterdam
SWI-Prolog comes with ABSOLUTELY NO WARRANTY. This is free software,
and you are welcome to redistribute it under certain conditions.
Please visit http://www.swi-prolog.org for details.

For help, use ?- help(Topic). or ?- apropos(Word).

[1,===,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20]
[1,2,===,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20]
[1,2,3,===,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20]
[1,2,3,4,===,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20]
[1,2,3,4,5,===,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20]
[1,2,3,4,5,6,===,7,8,9,10,11,12,13,14,15,16,17,18,19,20]
[1,2,3,4,5,6,7,===,8,9,10,11,12,13,14,15,16,17,18,19,20]
[1,2,3,4,5,6,7,8,===,9,10,11,12,13,14,15,16,17,18,19,20]
[1,2,3,4,5,6,7,8,9,===,10,11,12,13,14,15,16,17,18,19,20]
[1,2,3,4,5,6,7,8,9,10,===,11,12,13,14,15,16,17,18,19,20]
[1,2,3,4,5,6,7,8,9,10,11,===,12,13,14,15,16,17,18,19,20]
[1,2,3,4,5,6,7,8,9,10,11,12,===,13,14,15,16,17,18,19,20]
[1,2,3,4,5,6,7,8,9,10,11,12,13,===,14,15,16,17,18,19,20]
[1,2,3,4,5,6,7,8,9,10,11,12,13,14,===,15,16,17,18,19,20]
[1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,===,16,17,18,19,20]
[1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,===,17,18,19,20]
[1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,===,18,19,20]
[1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,===,19,20]
[1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,===,20]
false.


% halt