I'm trying to use the FOL KB in fol.lisp, and the only doc I found is
I want to be able to tell and ask FOL sentences, but I'm getting the
following errors, can anybody help please!
CG-USER(11): (setf kb (make-fol-kb))
#S(FOL-KB :POSITIVE-CLAUSES #<EQ hash-table with 0 entries @
:NEGATIVE-CLAUSES #<EQ hash-table with 0 entries @
CG-USER(12): (tell kb "(forall(x,P(x)))")
CG-USER(15): (ask kb '(forall (x) (P x)))
Error: Attempt to take the value of the unbound variable `???'.
[condition type: UNBOUND-VARIABLE]