[rules-users] Problem with Negative Patterns and Temporal Constraints

Hi all! We have the problem that the following rule never fires: rule "test-rule" agenda-group "evaluation" salience 100 when $cue : AnalysisCue() from entry-point "LowLevelCueStream" not(AnalysisCue(this after[0ms,2500ms] $cue) from entry-point "LowLevelCueStream") then logger.debug("... some message .."); end We found out that the problem is the combination of the negation with the conditional element "not" and the temporal constraint "[0ms,2500ms]". Using the temporal operator "this after $cue" without a temporal constraint works correct in its semantics. Interestingly, when adding a constraint (cueType == 1) to the type in the negative pattern the rule begins to work. The rule would look like as follows: rule "test-rule" agenda-group "evaluation" salience 100 when $cue : AnalysisCue() from entry-point "LowLevelCueStream" not(AnalysisCue(cueType == 1, this after[0ms,2500ms] $cue) from entry-point "LowLevelCueStream") then logger.debug("... some message .."); end unfortunately the rule then fires with a delay of 4 to 5 seconds. The second parameter of the temporal constraint influences the delay. When changing the first parameter of the temporal constraint to a value greater than 0 the rule works as expected! The constraint would then look like as follows: "[1ms, 2500ms]". Whereas in our case, we want to evaluate the time window from 0 - 2500ms. Our system works in the stream mode and we could reproduce this behaviour with the versions 5.3.1 and 5.4.0 Beta 1. Can anybody confirm if this is a bug in Drools, or did I overlook here something? Best regards, Wolfgang Weiss