Hi all, I encountered the following strange inconsistent behavior with the eclipse IDE and the Drools compiler. I have the following test rule which should fire if a specific time condition is present. The time condition is evaluated by a function called getTimelineDescriptor() which is imported using import function. rule "ScheduleTime: request for explicit time arrived" when ConditionMatrix(descriptors.times.timeline contains getTimelineDescriptor(EButtonID.TIME_SPECIFIC) || descriptors.times.timeline contains getTimelineDescriptor(EButtonID.DYNAMIC_ABSOLUTE_TIME) || descriptors.times.timeline contains getTimelineDescriptor(EButtonID.DYNAMIC_RELATIVE_TIME), $srcAlt: srcWorkingAlternative, ) then //something... end the IDE indicates an error on the conditionMatrix line with the following description: Multiple markers at this line - [ERR 101] Line 123:77 no viable alternative at input '(' in rule "ScheduleTime: request for explicit time arrived" in pattern ConditionMatrix - [ERR 102] Line 123:103 mismatched input '||' expecting 'then' in rule "ScheduleTime: request for explicit time arrived" - [ERR 101] Line 123:101 no viable alternative at input ')' in rule "ScheduleTime: request for explicit time arrived" in pattern getTimelineDescriptor BUT it compiles ok and runs properly. When I wrap the function with brackets (as I thought it should be) like this rule "ScheduleTime: request for explicit time arrived" when ConditionMatrix(descriptors.times.timeline contains (getTimelineDescriptor(EButtonID.TIME_SPECIFIC)) || descriptors.times.timeline contains (getTimelineDescriptor(EButtonID.DYNAMIC_ABSOLUTE_TIME)) || descriptors.times.timeline contains (getTimelineDescriptor(EButtonID.DYNAMIC_RELATIVE_TIME)), $srcAlt: srcWorkingAlternative, ) then //something... end the IDE shows no error but the compilation fails with the following error: 16:19:14,734 [ERROR] [LoggerStream]: Unable to Analyse Expression descriptors.times.timeline contains (getTimelineDescriptor(EButtonID.TIME_SPECIFIC)) || descriptors.times.timeline contains (getTimelineDescriptor(EButtonID.DYNAMIC_ABSOLUTE_TIME)) || descriptors.times.timeline contains (getTimelineDescriptor(EButtonID.DYNAMIC_RELATIVE_TIME)): [Error: unable to resolve method using strict-mode: com.delegatecom.rules.ConditionMatrix.contains(com.delegatecom.nlp.api.Timel ineDescriptor)] [Near : {... tors.times.timeline contains (getTimelineDescripto ....}] I am using Drools 5.2 with Helios (Eclipse). Any ideas why this is so? Although I have a working option it is impossible to maintain code when there are error indications. Thanks, Hezi