>You can go into an existing function and change what it does by manipulating or outright replacing its code. I still don't see what this might mean. It doesn'

>You can go into an existing function and change what it does by manipulating or outright replacing its code. I still don't see what this might mean. It doesn't sound like anything I've ever done in Scheme or I've ever heard of anyone else doing. You probably don't mean editing Scheme source code and recompiling.