Hi. I know this is a newbie question, but there is something I don't understand about globals. I am writing a piece of code, and I refer to "a class" that does exist. Suppose: testSomething NonExistenteClass Whem I accept the method, a popup brings saying it doesn't exist...etc. Then, I can define as global. If I then evaluate: Smalltalk globals at: #NonExistenteClass the key exist and it has nil as value. Perfect. So..if I understand well, all these globals variables AND classes are stored in this globals, which is the only instance of SystemDictionary (for the moment). Now my question is, where are nil, true, false, etc stored? I know there are only one instance of UndefinedObject, False, True, etc have only one instance...but WHERE are they stored? who keep them? They don't seem to be in SystemDictionary. Why no? I did a "chase pointers" to nil for example, and it says "CLASS: SmalltalkImage class subclasses: UndefinedObject" I still don't understand :( Thanks for any hints Mariano