Dear Robin,
It is fun to see a number of essays (Larissa's as well, on the animats) wrestle with the problem of defining "information processing" in a deeper, more rigorous fashion. And it's exciting to think that OK, we may actually be getting beyond what computer scientists have done in the past, which is to define computation as something useful to a third party.
Perhaps because computer scientists had to cleave off from the engineering department, they've been very reluctant to examine the underlying "physics" of their field--the study of the causal/mechanistic structures that underlie computation, and the generic properties we expect them to have.
It would be fun to apply the paradigm from the Information Theory of Individuality paper to a few toy examples. You could give some of your functions to agents in a little interacting system and give it a shot. I'd be curious to see what would happen, and whether the results would be illuminating. It would make a fun little paper.
Yours,
Simon
