[rules-users] Drool Rule Error with "or not" condition

Hi All, I have the following drool rule that has "or not" under Entity Block. Basically, the rule tries to check if there either exists an entity object EtsExecutionOrderXref_core00 with the given conditions, or the entity does not exist at all with some other conditions. dialect "mvel" rule "Legacy ETSDB Rule" when EtsExecutionOrderHist_core0:EtsExecutionOrderHist_core(customerOrFirm != "0") EtsExecutionOrderXref_core00: ( EtsExecutionOrderXref_core ( entityOID == EtsExecutionOrderHist_core0.entityOID , entityRID == EtsExecutionOrderHist_core0.entityRID , entityVID == EtsExecutionOrderHist_core0.entityVID , referenceID != "2" && referenceIDType == "orderSubCapacity" ) or not(EtsExecutionOrderXref_core ( entityOID == EtsExecutionOrderHist_core0.entityOID , entityRID == EtsExecutionOrderHist_core0.entityRID , entityVID == EtsExecutionOrderHist_core0.entityVID , referenceIDType == "orderSubCapacity" )) ) then end But, while compiling the rule, I am getting the following errors: org.drools.compiler.DroolsParserException: [ERR 101] Line 22:16 no viable alternative at input 'entityOID' in rule "Legacy ETSDB Rule" in pattern not, org.drools.compiler.DroolsParserException: [ERR 102] Line 22:68 mismatched input ',' expecting '(' in rule "Legacy ETSDB Rule" in pattern EtsExecutionOrderHist_core0.entityOID, org.drools.compiler.DroolsParserException: [ERR 102] Line 22:122 mismatched input ',' expecting '(' in rule "Legacy ETSDB Rule" in pattern EtsExecutionOrderHist_core0.entityOID in pattern EtsExecutionOrderHist_core0.entityRID, org.drools.compiler.DroolsParserException: [ERR 102] Line 22:176 mismatched input ',' expecting '(' in rule "Legacy ETSDB Rule" in pattern EtsExecutionOrderHist_core0.entityOID in pattern EtsExecutionOrderHist_core0.entityRID in pattern EtsExecutionOrderHist_core0.entityVID] I think the rule is correct, but am not able to figure out these compilation errors. Could anybody please comment on why this would happen? Thanks Malay Shah -------------------------------------------------------------------------- NOTICE: If received in error, please destroy, and notify sender. Sender does not intend to waive confidentiality or privilege. Use of this email is prohibited when received in error. We may monitor and store emails to the extent permitted by applicable law.