$ cat helloworld.swi
Result:
main :-
write('Hello, World!\n').
Command:
$ swipl
Result:
Welcome to SWI-Prolog (Multi-threaded, 64 bits, Version 7.2.3)
Copyright (c) 1990-2015 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).
Command:
?- ['helloworld.swi'].
Result:
true.
Command:
?- main.
Result:
Hello, World!
true.