completeness and forall

Hello.

I have a question regarding the use of the forall statement and the
completeness of results. As long as i know, the usage of horn articles
ensure, that cosulting my knwoledge base, wrong assumptions are
discovered to be wrong after finite time. (completeness!).

Now i use the forall statement of prolog which is written as:

forall(Cond, Action) :-
\+ (Cond, \+ Action).

I don't know if i'm wrong now, but is it right, that this is not
complete any longer?

Regards,

Alex

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