To implement things correctly, UDT needs to determine its entire strategy all at once.
Conceptually, yes. The point is that you don’t need to actually literally explicitly compute your entire strategy at t=-∞. All you have to do is prove a particular property of the strategy (namely, its action in situation Y) at the time when you are asked for a decision.
Obviously, like every computational activity ever, you must still make approximations, because it is usually infeasible to make inferences over the entire tegmark-IV multiverse when you need to make a decision. An example of such approximations would be neglecting the measure of “entities that give it rewards based on some combination of [newcomb’s and counterfactual mugging]” in many situations because I expect such things to be rare (significantly rarer than newcomb’s and counterfactual mugging themselves).
Conceptually, yes. The point is that you don’t need to actually literally explicitly compute your entire strategy at
t=-∞. All you have to do is prove a particular property of the strategy (namely, its action in situation Y) at the time when you are asked for a decision.Obviously, like every computational activity ever, you must still make approximations, because it is usually infeasible to make inferences over the entire tegmark-IV multiverse when you need to make a decision. An example of such approximations would be neglecting the measure of “entities that give it rewards based on some combination of [newcomb’s and counterfactual mugging]” in many situations because I expect such things to be rare (significantly rarer than newcomb’s and counterfactual mugging themselves).