Thanks for the response. To clarify, I'm not trying to point to the AIXI framework as a promising path; I'm trying to take advantage of the unusually high degree of formalization here in order to gain clarity on the feasibility and potential danger points of the "tool AI" approach.

It sounds to me like your two major issues with the framework I presented are (to summarize):

(1) There is a sense in which AIXI predictions must be reducible to predictions about the limited set of inputs it can "observe directly" (what you call its "sense data").

(2) Computers model the world in ways that can be unrecognizable to humans; it may be difficult to create interfaces that allow humans to understand the implicit assumptions and predictions in their models.

I don't claim that these problems are trivial to deal with. And stated as you state them, they sound abstractly very difficult to deal with. However, it seems true - and worth noting - that "normal" software development has repeatedly dealt with them successfully. For example: Google Maps works with a limited set of inputs; Google Maps does not "think" like I do and I would not be able to look at a dump of its calculations and have any real sense for what it is doing; yet Google Maps does make intelligent predictions about the external universe (e.g., "following direction set X will get you from point A to point B in reasonable time"), and it also provides an interface (the "route map") that helps me understand its predictions and the implicit reasoning (e.g. "how, why, and with what other consequences direction set X will get me from point A to point B").

Difficult though it may be to overcome these challenges, my impression is that software developers have consistently - and successfully - chosen to take them on, building algorithms that can be "understood" via interfaces and iterated over - rather than trying to prove the safety and usefulness of their algorithms with pure theory before ever running them. Not only does the former method seem "safer" (in the sense that it is less likely to lead to putting software in production before its safety and usefulness has been established) but it seems a faster path to development as well.

It seems that you see a fundamental disconnect between how software development has traditionally worked and how it will have to work in order to result in AGI. But I don't understand your view of this disconnect well enough to see why it would lead to a discontinuation of the phenomenon I describe above. In short, traditional software development seems to have an easier (and faster and safer) time overcoming the challenges of the "tool" framework than overcoming the challenges of up-front theoretical proofs of safety/usefulness; why should we expect this to reverse in the case of AGI?