About @@max in tapestry

You can call a static method using the syntax @class@method(args). If
you leave out class, it defaults to java.lang.Math, to make it easier to
call min and max methods. If you specify the class, you must give the
fully qualified name.

If you have an instance of a class whose static method you wish to call,
you can call the method through the object as if it was an instance method.

If the method name is overloaded, OGNL chooses the right static method
to call using the same procedure it uses for overloaded instance methods.