It occurs to me that Jaynes is missing a desideratum that I might have included. I can't decide if it's completely trivial, or if perhaps it's covered implicitly in his consistency rule 3c; I expect it will become clear as the discussion becomes more formal -- and of course, he did promise that the rules given would turn out to be sufficient. To wit:

• The robot should not assign plausibilities arbitrarily. If the robot has plausibilities for propositions A and B such that the plausibility of A is independent of the plausibility of B, and the plausibility of A is updated, then the degree of plausibility for B should remain constant barring other updates.

One more thing. The footnote on page 12 wonders: Does it follow that AND and NOT (or NAND alone) are sufficient to write any computer program?

Isn't this trivial? Since AND and NOT can together be composed to represent any logic function, and a logic function can be interpreted as a function from some number of bits (the truth values of the variable propositions) to one result bit, it follows that we can write programs with AND and NOT that make any bits in our computer an arbitrary function of any of the other bits. Is there some complication I'm missing?

(Edited slightly for clarity.)