Welcome to SWI-Prolog (Multi-threaded, Version 5.6.20) Copyright (c) 1990-2006 University of 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 123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789 Yes % halt