First of all thanks for your help.
On to my problem: Let's say I have:
some_fact:- true.
and I want to asserta a rule on top of it that looks like this:
some_fact:- fail, !.
This is because I want to transform the "some_fact:- true." to force a false without removing the rule (I don't want to use abolish(some_fact,0). )
The problem is that I can't find the way to do it because I can't place the comma on the asserta/1. What I mean is that when I put:
asserta(some_fact:- fail, !).
the comma in between forces a call to asserta/2 instead of asserta/1 with the whole rule, and I cannot prevent that using quotes because it asserts a string.
Of course I can't just simply put asserta(some_fact:- fail). because prolog will search for the next some_fact which returns true.
Any ideas? Thanks again!
just add parenthesis:
?- asserta((some_fact:- fail, !)).
true.