Hello I am making some modifications in the smalltalk meta-model and i need to replace classes with Ring classes (it is supposed to be possible since they are polymorphic) But i am having a little problem, all the classes know how to answer the message "isObsolete" but Ring classes doesn't, to solve this i have defined the method "isObsolete" in RGBehaviorDefinition but i am not sure which code does it need - if i copy and paste the code from Behavior, then i obtain more "doesNotUnderstand" messages since the code from Behavior>>isObsolete is "self instanceCount = 0" but Ring classes doesn't know how to answer "instanceCount" neither so i suspect this is not the right way to do it. - if i copy the code from Class, then it seems it works, but the result from for example "Array isObsolete" is different of the result from "Array asRingDefinition isObsolete" consequently next messages obtain different results and finally a a "doesNotUnderstand" message again. Am i doing something wrong? Any suggestion?