Hello, I've been looking at implementation of Associtation and LookupKey (its superclass). In LookupKey, there is LookupKey>>#= and LookupKey>>#hash both implemented to use key (compare keys and use hash of key), but in Association, Association>>#= compares both key and value, but hash is not changed there, so only hash of key is used, therefore it does not correspond to implementation of method = ... shouldn't it? To demonstrate: (1 -> #a) = (1 -> #b). is false but (1 -> #a) hash = (1 -> #b) hash. is true I also noticed similar discussion for Doplhin smalltalk http://forum.world.st/Association-gt-gt-hash-td3368868.html where guys state it is all right, but I still do not see why. Jan -- Sent from: http://forum.world.st/Pharo-Smalltalk-Developers-f1294837.html