If I understand your question correctly, it boils down to asking how long is a minimal implementation of the AIXItl algorithm. The answer to that is, pretty short; it would fit in one page of code. (This fact is of little practical importance, of course, since it would still require much more computation than is possible according to our current understanding of physics.)
It's possible I'm not understanding your question correctly, in which case please point out what I'm missing.
I agree with this.
K(AIXItl) <= length of code that Hutter actually took to write it ~ 300 lines of code.
With respect to a minimal state-symbol turing machine it would be 300 + (however much it takes to translate common math concepts like "argmax" into the minimal state-symbol turing machine's language).
Does anyone happen to know the Komogorov complexity (in some suitable, standard UTM -- or, failing that, in lines of Python or something) of computable approximations of AIXI?
I'm writing a paper on how simple or complicated intelligence is, and what implications that has for AI forecasting. In that context: adopt Shane Legg's measure of intelligence (i.e., let "intelligence" measure a system's average goal-achievement across the different "universe" programs that might be causing it to win or not win reward at each time step, weighted according to the universe program's simplicity).
Let k(x, y) denote the Kolmogorov complexity of the shortest program that attains an intelligence of at least x, when allowed an amount y of computation (i.e., of steps it gets to run our canonical UTM). Then, granting certain caveats, AIXI and approximations thereto tell us that the limit as y approaches infinity of k(x,y) is pretty small for any computably attainable value of x. (Right?)
What I'd like is to stick an actual number, or at least an upper bound, on "pretty small".
If someone could help me out, I'd be much obliged.