On 30/07/2013, Aurelien Mazurie <ajmazu...@oenone.net> wrote: > Thank you very much for this answer. It seems like 'forall' will fire the > rule only if all the 'bag-of-items' facts are validated (i.e., if all of > them have 'item' facts with the names listed in their 'names' slot). Is that > correct?
Yes. > > If yes, then what I am trying to do is slightly different. I do expect to > have some of the 'bag-of-items' facts failing the validation. What I want is > to act upon those who pass (and also, incidentally, on those who do not > pass). Ernest's rule fires on the "pass" set. > > Is there a way to keep track of which, among all the 'bag-of-items' facts, > are validated by the 'forall' CE? The negation of the "forall" is the negated existential quantifier, thus: (defrule check-bag-NOT-valid (bag-of-items (names $? ?name $?)) (not (item (name ?name))) => (printout t "The bag contains invalid " ?name crlf)) The rule fires for each of the bad items in a bag. Sometimes this is desired. If not, the bad bag might be retracted or marked as "bad" in an additional slot. -W > > Best, > Aurélien > > ps: 'dynamic' may be a poor choice of words. I meant that the LHS had to > dynamically adapt to the content of a fact's multislot, different from one > fact to another > > On Jul 30, 2013, at 8:21 AM, "Friedman-Hill, Ernest [via Jess]" > <ml-node+s2305737n4654179...@n4.nabble.com> wrote: > >> Not sure what "dynamic" means in this context. But you can use the >> "forall" conditional element to implement this rule. You could read the >> LHS here as "For all values of ?name in bag-of-items, there's a >> corresponding item fact." >> >> (defrule check-bag-valid >> (forall >> (bag-of-items (names $? ?name $?)) >> (item (name ?name))) >> => >> (printout t "The bag is valid" crlf)) >> >> NOTE: Like many complex Jess rules, this one won't fire unless before >> adding your facts you've executed the "(reset)" command to asset >> (initial-fact). > > > > > > -- > View this message in context: > http://jess.2305737.n4.nabble.com/Dynamic-rule-matching-in-the-LHS-tp4654176p4654180.html > Sent from the Jess mailing list archive at Nabble.com. -------------------------------------------------------------------- To unsubscribe, send the words 'unsubscribe jess-users y...@address.com' in the BODY of a message to majord...@sandia.gov, NOT to the list (use your own address!) List problems? Notify owner-jess-us...@sandia.gov. --------------------------------------------------------------------
