Although we strongly advice to put your program in a file, optionally
edit it and use make/0
to reload it (see section
2.1.4), it is possible to manage facts and rules from the terminal.
The most convenient way to add a few clauses is by consulting the pseudo
file
user. The input is ended using the system end-of-file
character.
?- [user].
|: hello :- format('Hello world~n').
|: ^D
true.
?- hello.
Hello world
true.
The predicates assertz/1 and retract/1 are alternatives to add and remove rules and facts.