Polymorphism in the OO world is implemented with function reference.  Every object class has a "function" variable, of which every element is a definition of a function name.  For example:

var car1%model = "Camry";

var car2%model = "Diablo";

var car1%function:whatType = "familyCar";

var car2%function:whatType = "playCar";

function familyCar

{

   display "{this%model} is a car for the family.";

}

function playCar

{

   display "{this%model} is for fun.";

}

car1%whatType;  // Camry is a car for the family.

car2%whatType;  // Diablo is for fun.