Thanks! This is exactly what I need. As you can see in my follow up email, I tried to do this transformation, but for some odd reason I think it was my placement of (watch all) - I didn¹t see all the assertions. However, I still have the endless loop issue if I combine this with the removeTransformation rule.
On 9/7/07 9:40 AM, "Robert Kirby" <[EMAIL PROTECTED]> wrote: > This can all be combined in a single rule without a "foreach" loop. > > (defrule manage-source-templates > "Logically assert or retract templates for source" > (logical (source (id ?id) (templates $? ?template $?))) > (not (transform (source ?id) (template ?template))) > => > (assert (transform (source ?id) (template ?template)))) > > Bob Kirby > > At 09:11 AM 9/7/2007, Ernest Friedman-Hill wrote: >> Same idea: >> >> (defrule removeTransforms >> ?t <- (transform (source ?id) (template ?t)) >> (not (source (id ?id)(templates $? ?t $?)) >> => >> (retract ?t)) >> >> >> On Sep 7, 2007, at 11:57 AM, Hal Hildebrand wrote: >>> Doh! That does work well and I'll certainly replace my cheesy >>> solution with this, but one of the issues I'm dealing with is that the set >>> of templates can change and I would like to ensure that as changes to the >>> list of templates occur, the corresponding transforms are asserted or >>> retracted. >>> Sorry, this is an additional constraint I would like to satisfy that I >>> should have noted. >>> >>> >>> On 9/7/07 8:28 AM, "Wolfgang Laun" <[EMAIL PROTECTED]> >>> wrote: >>>> Assuming that the absence of any "transform" fact with a "source" >>>> slot equal to the "id" slot of a new "source" fact is the criterion for >>>> creating the "transform" facts: >>>> >>>> (defrule makeTransforms >>>> ?s <- (source (id ?id)(templates $?templates)) >>>> (not (transform (source ?id))) >>>> => >>>> (foreach ?temp $?templates >>>> (assert (transform (source ?id) (template ?temp)))) >>>> ) >>>> >>>> kr >>>> Wolfgang >>>> >>>> Hal Hildebrand wrote: >>>>> I have a system where I need to ensure that for every member of a >>>>> list, there is a fact which contains that member. For example, here's >>>>> my domain: >>>>> >>>>> >>>>> (deftemplate source (slot id) (multislot templates)) >>>>> (deftemplate transform (slot source) (slot template)) >>>>> >>>>> >>>>> What I would like is to write some rules that ensure that for ever member >>>>> of the templates slot of a "source", I have a corresponding transform. If >>>>> I assert: >>>>> >>>>> (assert source (id 1) (templates (create$ a b c))) >>>>> >>>>> I would like to see three facts asserted in response: >>>>> >>>>> (assert transform (source 1) (template a)) >>>>> (assert transform (source 1) (template b)) >>>>> (assert transform (source 1) (template c)) >>>>> >>>>> >>>>> I have accomplished this by creating an intermediary fact and some rules >>>>> which essentially cycle through the list of templates in the source, >>>>> asserting a transform for each. However, this just feels wrong. It seems >>>>> like I should be able to express this without the intermediary facts. >>>>> >>>>> Perhaps this is where backward chaining would be useful? Or perhaps I can >>>>> use the new "accumulate" CE? Or, have I already found the solution using >>>>> an intermediary fact to cycle through the list of templates? >>>>> >>>>> Any help/suggestions would be appreciated. >> >> --------------------------------------------------------- >> Ernest Friedman-Hill >> Advanced Software Research Phone: (925) 294-2154 >> Sandia National Labs FAX: (925) 294-2234 >> PO Box 969, MS 9012 [EMAIL PROTECTED] >> Livermore, CA 94550 http://www.jessrules.com >
