You have to establish the age of one applicant as bound to a variable so that you
can ascertain this being equal to the age of all Applicants.

rule "age-2"
when
    $list : List( size > 0 )  # ensure non-empty so that get(0) doesn't NPE
    forall( Applicant( $age : age == ( ((Applicant)$list.get(0)).getAge() ) ) from $list )
then
    System.out.println( "success" );
end

On 15 September 2010 09:52, tushmish <Tushar.Mishra@lntinfotech.com> wrote:

rule "age"
       when
               $list : List();
               forall( $app : Applicant( $age : age) from $list
                  Applicant( this == $app, age == $age ) );
       then
               System.out.println("success" );
end


It's noteworthy that this rule would fire if you insert all Applicant objects that are in the List as 1st order facts. What is does is

   forall( $app | $app in List &
                         forall ( $f | $f in WM & $f instanceof Applicant & $f == $app & $f.age == $app.age ) )

where the inner "forall" is implied by the general fact matching algorithm. The last term of the inner conjunction is redundant as we have established the identity by $f == $app - the pattern just matches all list elements with themselves.

-W