The rightmost list box displays operators for comparing objects. Any two objects can be compared because the class Object provides a default implementation. This means that the method is implemented at a low level for efficiency and we can't view the implementation. With the middle button click over the left list box. Select comment from the popup menu.
Most classes have a comment with some description of themselves.
With the middle button, click over the left list box. This displays the definitions of the classes' instance variables and class variables. The class Object is the only class with a nil superclass. It has Object as its superclass. It has Model as its superclass.