When using the conditional element NOT together with FROM e.g.
rule "rulename" when $t : Tariffs( ) not TariffItemList ( ) from $t.getTariffItemLists() then //Do something end
The Tariffs object contains a list of TariffItem objects.
You might get a rule compilation error similar to:
org.drools.rule.InvalidRulePackage: 9830: unknown:98:30 mismatched token: [90327422745from529830|@903,2742:2745='from',<52>,98:30]; expecting type THEN
The error indicates the location of the problem which in this case is character 30 on line 98 - this is handy when you have a large number of rules in a single DRL file and the rule that caused the failure is not reported.
The compiler is reporting that your syntax is incorrect.
The correct syntax is:
rule "rulename" when $t : Tariffs( ) not ( TariffItemList ( ) from $t.getTariffItemLists() ) then //Do something end