What does this equation mean?

IDA is debate’s closest theoretical relative, aimed at the same underlying worry from a different angle: rather than trusting a single judge to adjudicate an argument about a hard problem, it never asks any one evaluator to face the hard problem directly. Christiano, Shlegeris, and Amodei describe a scheme they call Amplify: a composite system, written $\mathrm{Amplify}_H(X)$ , “consisting of H and several copies of X working together to solve a problem,” in which H — standing in for a human overseer — breaks a hard question into useful subquestions, has several copies of the current trained agent X answer each subquestion, and then combines the subanswers into a response to the original question [ 11 ] . The trained agent is then updated to imitate that amplified process directly: “the agent X then learns from $\mathrm{Amplify}_H(X)$ in the same way that it would traditionally learn from H alone” [ 11 ] . Run repeatedly, the described process is naturally read as the recursion $X_{t+1} \;=\; \mathrm{Distill}\big(\mathrm{Amplify}_H(X_t)\big)$. with each iteration’s agent trained to imitate the amplified, decomposed judgment of the previous iteration rather than any single overseer’s raw judgment of the whole problem. The paper describes the intended trajectory in prose rather than in this compact notation, but the substance is the same: over successive iterations, “the agent X becomes more powerful and the role of the expert transitions into ‘coordinating’ several copies of X to solve the problem better than a single copy could solve it” [ 11 ] .