[rules-users] Finicky eval statements

I'm puzzled over the proper use of in-line evals. I've used them successfully in some places. But it seems that on occasion something doesn't work when I think it should. First, this is a when clause that works properly using a separate eval statement. The rule activates and fires when expected: $rt : RuleTimer(uniqueName == "Hardware Status Request", timedOut == true) $hw : Hardware($activelyMonitored : activelyMonitored, command == null) AttrBoolean(this == $activelyMonitored, currentValue == true) eval($hw.getStatusRequested().howOld() > $hw.getStatusPeriod()) However, this re-write changing to an in-line eval never fires. $rt : RuleTimer(uniqueName == "Hardware Status Request", timedOut == true) $hw : Hardware($activelyMonitored : activelyMonitored, command == null, eval(statusRequested.howOld() > statusPeriod) ) AttrBoolean(this == $activelyMonitored, currentValue == true) Likewise, this re-write doesn't fire either where I sought to bind the more complex statusRequested object to a Drools variable before using it in the eval. The field statusPeriod just holds a primitive double. $rt : RuleTimer(uniqueName == "Hardware Status Request", timedOut == true) $hw : Hardware($activelyMonitored : activelyMonitored, $sr : statusRequested, command == null, eval($sr.howOld() > statusPeriod) ) AttrBoolean(this == $activelyMonitored, currentValue == true) I haven't been able to find anything in the manual that says these other two syntaxes are wrong. Furthermore, the Drools compiler has no issues with them. Thanks! Allen F. Bagwell e-mail: afbagwe(a)sandia.gov phone: 505/284-4517 fax: 505/ 844-7886 Ask your doctor if medical advice from a TV commercial is right for you.