JESS: multislot pattern matching using "accumulate"

(defrule VALIDATE:dataset-variables
    (page "edit-dataset.xslt")
    ?dataset <- (dataset (variables $?) (has-errors FALSE))
    ?errors <- (accumulate (bind ?list (new java.util.ArrayList))   
                        (?list add ?var)
                         ?list
                        (dataset (variables $? ?var&:
                                (not (regexp "^[a-zA-Z_][a-zA-Z0-9_\\.]*$" ?var)) $?)))
=>
    (printout t "errors = " (?errors toString) crlf)
    (modify ?dataset
        ; TODO: set variablesErrors for each variable in ?errors"
        (has-errors TRUE)))

It looks like this works and is very cool but if I have more then one dataset how do I get the ?dataset and ?errors to correlate?

test-facts.clp
...
(page "edit-dataset.xslt")

(dataset
    (name "testdata")
    (nobs "120")
    (nvars "10")
    (variables "X1" "X-2" "X3")
    (submitEditDatasetForm "Submit"))
...

This copy of Jess will expire in 106 day(s).
executing...
errors = [X-2]
f-0   (MAIN::initial-fact)
f-1   (MAIN::nextPage "edit-dataset.xslt")
f-2   (MAIN::R nil)
f-3   (MAIN::subscription-prices (maxDataElements 500) (monthlyPrice 25) (yearlyPrice 100))
f-4   (MAIN::upload-info (uploadDirectory "/tmp/Rserv") (filename "test.csv") (contentType "text/plain") (contentTypeError "") (length 53) (format "fwf") (separationChar ",") (columnWidths "2 8 10 5 15") (hasColumnNames "TRUE") (submitUploadForm nil) (submitDatasetForm nil) (submitShowDatasetForm nil) (has-errors FALSE))
f-5   (MAIN::page "edit-dataset.xslt")
f-6   (MAIN::dataset (name "testdata") (nameError "") (nobs "120") (nvars "10") (variables "X1" "X-2" "X3") (variableErrors ) (variableTypes ) (submitEditDatasetForm "Submit") (has-errors TRUE) (isFree TRUE))
f-7   (MAIN::purchase-info (creditCardNumber "1408 0412 3456 7893") (creditCardNumberError "") (creditCardType "") (securityCode "143") (securityCodeError "") (expirationDate "05-2010") (expirationDateError "") (nameOnCard "Donald P Winston") (nameOnCardError "") (subscription nil) (subscriptionError "") (submitPurchaseSubscriptionForm nil) (has-errors FALSE))
For a total of 8 facts in all modules.

Donald Paul Winston
[email protected]