JESS: Ordered facts and list problems

[Ana Tanasescu]

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Hello everyone,

 

I have the following problem. I want to find in my working memory the ordered facts with the same second element and to generate a fact that contains this element and the other elements after him.

So if I have the following facts:

(fact e1 a) (fact e1 b) (fact e1 c) (fact e1 d)

I want to obtain a fact like this (final e1 a b c d).

 

Because I didn’t know how to do this, I have tried to use queries and generate a list with the following structure (e1 a b c d).

Unfortunately, after I run the code:

(deffacts factslist

    (fact e1 a)

    (fact e1 b)

    (fact e1 c)

    (fact e1 d))

 

(reset)

 

(defquery search-by-name

(declare (variables ?e1))

(fact ?e1 ?e2))

 

(bind ?result (run-query* search-by-name e1))

 

(while (?result next)

(bind ?list (create$ (?result getSymbol e1)(?result getSymbol e2))))

 

(printout t "List is " ?list  crlf)

 

The result is (e1 d).

What should I do?

 

Best regards,

Ana

[Neelakantan Kartha]

I am trying to write a rule to check whether a package (chosen by a user
via a UI) is appropriate for a location. If the chosen
package is not appropriate, we want to warn the user.

Here is a simplified version of the domain

(deftemplate box (slot id)(multislot objects)) ;boxes can contain
multiple objects
(deftemplate location (slot id) (slot need)) ;locations have needs,
which are integers
(deftemplate satisfies-need (slot box) (slot location) (slot object))
;some objects in a box can satisfy a need of a location.
(deftemplate pkg (slot package-name)(slot location) (multislot boxes)) ;
a package for a location consists of multiple boxes.
(deftemplate satisfies-need-pkg (slot package-name)(slot location))

(assert (box (id b1) (objects o1 o2)))
(assert (box (id b2) (objects o3 o4)))
(assert (box (id b3) (objects o5 o6)))
(assert (box (id b4) (objects o7 o8 o9)))
(assert (box (id b5) (objects o10 o11 o12)))

(assert (location (id l1) (need 3))) ;location l1 has 3 needs

(assert (satisfies-need (box b1) (location l1) (object o1))); object o1
satisfies a need of location l1
(assert (satisfies-need (box b2) (location l1) (object o3))); object o3
satisfies a need of location l1
(assert (satisfies-need (box b3) (location l1) (object o6))); object o6
satisfies a need of location l1

;The following might be asserted as a result of the user defining a
package using the UI.
(assert (pkg (package-name p1)(location l1) (boxes b1 b2))) ; user
chooses a pakckage p1 consisting of boxes b1 and b2
(assert (pkg (package-name p2)(location l1) (boxes b1 b2 b3))); user
chooses a package p2 consisting of boxes b1, b2 and b3.

  To see whether a package satisfies the need at a location, we do the
following. Initialize count to zero.
     (a) Look at each box (call it b) in the package and look at each
object  inside b. If that object
         satisfies the need at the location, we add 1 to count.
Otherwise we do nothing.
     (b) If the count at the end is greater than or equal to the value
of the  need slot of the location, the package
          satisfies the need.
   
     Example: Package p1 does not satisfy the need of location 1, since
the count is only 2  (due to o1 and o3)and the need is 3
              Package p2 does satisfy the need of location l (from o1,
o3 and o6)
   
    Note that the satisfied-need facts are asserted as a result of other
rule firings to determine whether
    an object does satisfy the need of a location (and thus are not
directly asserted as in the example above).

The question is how do I write a rule to determine whether a package
satisfies a need for  a location:

(defrule satisfies-need-pkg
 
    ?????
   
    ==>
    (assert (satisfied-need-pkg (package-name $p) (location $l)))
    )


It seems that I should be able to use accumulate CE, but I am having a
hard-time making it work. Any suggestions on how to do this (with or
without using the accumulate CE)

Thanks,

Kartha




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[Ernest Friedman-Hill]

On Oct 5, 2009, at 5:45 PM, ANA TANASESCU wrote:

>
> (while (?result next)
>     (bind ?list (create$ (?result getSymbol e1)(?result getSymbol  
> e2))))
>
> (printout t "List is " ?list  crlf)


Each time through this loop, you create a new list containing a single  
element and bind it to ?list; at the end of the loop, of course ?list  
contains just the single list you created on the last iteration.  This  
is really no different from what would happen if you wrote similar  
code in Java. If you want to add to the list, then each call to create
$ should include the previous value of the list as part of the new  
list; i.e.


(bind ?list (create$ e1))
(while (?result next)
     (bind ?list (create$ ?list (?result getSymbol e2)))

After this loop, ?list will be (e1 a b c d) .

---------------------------------------------------------
Ernest Friedman-Hill
Informatics & Decision Sciences, Sandia National Laboratories
PO Box 969, MS 9012, Livermore, CA 94550
http://www.jessrules.com







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[Wolfgang Laun-2]

This is my solution:

; satisfying package/location/object combinations
(deftemplate fit (slot package-name)(slot location)(slot object))

; create the fits
(defrule sat1
    (pkg (package-name ?p)(location ?l)(boxes $? ?b $?))
    (box (id ?b) (objects $? ?o $?))
    (satisfies-need (box ?b) (location ?l) (object ?o))
  =>
  (printout t "rule sat1 - package " ?p " location " ?l " object " ?o  crlf)
  (assert (fit (package-name ?p)(location ?l)(object ?o)))
)

; count the fits
(defrule sat2
  (location (id ?l) (need ?n))
  (pkg (package-name ?p)(location ?l))
  ?c <- (accumulate (bind ?count 0)
                    (bind ?count (+ ?count 1))
                    ?count
                    (fit (package-name ?p)(location ?l) (object ?o)))
  (test (>= ?c ?n))
  =>
  (printout t "rule sat2 fires - location " ?l " package " ?p " count " ?c  crlf)
  (assert (satisfied-need-pkg (package-name $p) (location $l)))
)

And you'll need a third, low-salience rule to get rid of the fits.

It would probably better to avoid multislots.

-W

On Tue, Oct 6, 2009 at 1:55 AM, Neelakantan Kartha <kartha@...> wrote:

I am trying to write a rule to check whether a package (chosen by a user via a UI) is appropriate for a location. If the chosen
package is not appropriate, we want to warn the user.

Here is a simplified version of the domain

(deftemplate box (slot id)(multislot objects)) ;boxes can contain multiple objects
(deftemplate location (slot id) (slot need)) ;locations have needs, which are integers
(deftemplate satisfies-need (slot box) (slot location) (slot object)) ;some objects in a box can satisfy a need of a location.
(deftemplate pkg (slot package-name)(slot location) (multislot boxes)) ; a package for a location consists of multiple boxes.
(deftemplate satisfies-need-pkg (slot package-name)(slot location))

(assert (box (id b1) (objects o1 o2)))
(assert (box (id b2) (objects o3 o4)))
(assert (box (id b3) (objects o5 o6)))
(assert (box (id b4) (objects o7 o8 o9)))
(assert (box (id b5) (objects o10 o11 o12)))

(assert (location (id l1) (need 3))) ;location l1 has 3 needs

(assert (satisfies-need (box b1) (location l1) (object o1))); object o1 satisfies a need of location l1
(assert (satisfies-need (box b2) (location l1) (object o3))); object o3 satisfies a need of location l1
(assert (satisfies-need (box b3) (location l1) (object o6))); object o6 satisfies a need of location l1

;The following might be asserted as a result of the user defining a package using the UI.
(assert (pkg (package-name p1)(location l1) (boxes b1 b2))) ; user chooses a pakckage p1 consisting of boxes b1 and b2
(assert (pkg (package-name p2)(location l1) (boxes b1 b2 b3))); user chooses a package p2 consisting of boxes b1, b2 and b3.

 To see whether a package satisfies the need at a location, we do the following. Initialize count to zero.
   (a) Look at each box (call it b) in the package and look at each object  inside b. If that object
       satisfies the need at the location, we add 1 to count. Otherwise we do nothing.
   (b) If the count at the end is greater than or equal to the value of the  need slot of the location, the package
        satisfies the need.
     Example: Package p1 does not satisfy the need of location 1, since the count is only 2  (due to o1 and o3)and the need is 3
            Package p2 does satisfy the need of location l (from o1, o3 and o6)
    Note that the satisfied-need facts are asserted as a result of other rule firings to determine whether
  an object does satisfy the need of a location (and thus are not directly asserted as in the example above).

The question is how do I write a rule to determine whether a package satisfies a need for  a location:

(defrule satisfies-need-pkg

  ?????
    ==>
  (assert (satisfied-need-pkg (package-name $p) (location $l)))
  )


It seems that I should be able to use accumulate CE, but I am having a hard-time making it work. Any suggestions on how to do this (with or without using the accumulate CE)

Thanks,

Kartha




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