Validation in drools

Question

This is the second part of my drools validation question. First part has been already answered and proposed solutions has been implemented in my code. First Part

This is

Answer 1

Added itemValue tests as seen in some comment

rule "land-orbuilding..."
when
  Peson( $financeDetails: financeDetails, $personAddress: personAddress )
  FinanceDetails( financeItemName == "Land or Building", itemValue == null || itemValue == 0 ) from $financeDetails
  PersonAddress( status == AddressStatus.CURRENT,
                 type == AddressType.PHYSICAL,
                 useType == AddressUseType.HOME,
                 ownerShipType == "Own" ) from $personAddress
then
  //...
end

How about reading some of that documentation? This is very much like the "first part", and only a minor variation.