The translation of

-- "What is P(A), for totally unspecified hypothesis A?"

-- "50%."

into AI-internal-speak is

-- "Okay, I'm about to feed you a binary string. What digits have I fed you so far?"

-- "Nothing yet."

You seem to be using a translation scheme that I have not encountered before. You give one example of its operation, but that is not enough for me to distill the general rule. As with all translation schemes, it will be easier to see the pattern if we see how it works on several different examples.

So, with that in mind, suppose that the AI were asked the question

-- "What is P(A), for a hypothesis A whose first digit is 1, but which is otherwise totally unspecified?"

What should the AI's answer be, prior to translation into "AI-internal-speak"?