<Validation name="CarValidation" enabled="True">
  <Declaration>
    <Define name="car" direction="In" />
  </Declaration>
  <Logic name="main">
    <And processAll="True">
      <Null negate="True" message="Car is required" value="car" />
      <Validate message="Car model must be provided" logic="NotNullOrEmpty" value="car.Model" />
      <Validate message="Car made must be provided" logic="NotNullOrEmpty" value="car.Made" />
    </And>
  </Logic>
  <Logic name="NotNullOrEmpty" variable="$v">
    <Or negate="True">
      <Null value="$v" />
      <Empty value="$v" />
    </Or>
  </Logic>
</Validation>