trying to be more concrete (and still not sure of pragma syntax and capabilities) I wonder if with methods in the image like: OSMorphicEventHandler>>accept: aMouseEvent <pragma: precondition parameter:aMouseEvent isKindOf: OSMorphicEvent> OSXWindowEvenHandlert>>accept: aMouseEvent <pragma: precondition parameter:aMouseEvent isKindOf: OSMorphicEvent> OSMarsWindowEvent>>accept: aMouseEvent <pragma: precondition parameter:aMouseEvent isKindOf: OSMorphicEvent> SignalHandler>>accept: aSignalEvent <pragma: precondition parameter:aSignalEvent isKindOf: SignalEvent> browsing OSWindowMorphicEventHandler>>handleEvent: OSWindowMorphicEventHandler>>handleEvent: morphicEvent := anEvent accept: self. or morphicEvent := anEvent accept: aVariableEvent. current class beeing a subclass of OSMorphicEvent (type of self), and aVariableEvent type beeing known (NEC/NEOController/model ?) it couldn't be possible to find or filter relevant methods for both, excluding SignalHandler (filtering on accept: methods with good pragma signature) ? Regards, Alain