Via Rice’s theorem, any non-trivial semantic property of an algorithm (such as whether it is extensionally equivalent to some other algorithm) is also undecidable.
This is about ability to answer such questions about all algorithms at once. There is no way to algorithmically tell if an arbitrary algorithm behaves the same as a given algorithm. But this is false for many specific algorithms, where it’s possible to decide all sorts of properties, for example proving that two particular algorithms always behave the same.
And it might be false-in-practice for the algorithm that’s running you. It’s inconvenient when you can know how this algorithm behaves, since then you need to take that into account in what kinds of thinking can be enacted with it, but it can happen. The chicken rule is a way of making this unhappen, by acting contrary to any fact about your algorithm’s behavior you figure out, so that you won’t be in a position to figure out such facts, on pain of contradiction.
This is about ability to answer such questions about all algorithms at once. There is no way to algorithmically tell if an arbitrary algorithm behaves the same as a given algorithm. But this is false for many specific algorithms, where it’s possible to decide all sorts of properties, for example proving that two particular algorithms always behave the same.
And it might be false-in-practice for the algorithm that’s running you. It’s inconvenient when you can know how this algorithm behaves, since then you need to take that into account in what kinds of thinking can be enacted with it, but it can happen. The chicken rule is a way of making this unhappen, by acting contrary to any fact about your algorithm’s behavior you figure out, so that you won’t be in a position to figure out such facts, on pain of contradiction.