At this point it seems simplest to construct your reference class so as to only contain agents that can be found using the same procedure as yourself. Since you have to be decidable for the hypothesis to predict your observations, all others in your reference class are also decidable.
Problem is, there isn’t necessarily a modular procedure used to identify yourself. It may just be some sort of hard-coded index. A Solomonoff inductor will reason over all possible such indices by reasoning over all programs, and throw out any which turn out to not be consistent with the data. But that behavior is packaged with the inductor, which is not itself a program.
At this point it seems simplest to construct your reference class so as to only contain agents that can be found using the same procedure as yourself. Since you have to be decidable for the hypothesis to predict your observations, all others in your reference class are also decidable.
Problem is, there isn’t necessarily a modular procedure used to identify yourself. It may just be some sort of hard-coded index. A Solomonoff inductor will reason over all possible such indices by reasoning over all programs, and throw out any which turn out to not be consistent with the data. But that behavior is packaged with the inductor, which is not itself a program.
Yes, I agree. “Reference class” is a property of some models, not all models.