I certainly don’t think agents “should” try to achieve outcomes that are impossible from the problem specification itself.
I think you need to make a clearer distinction here between “outcomes that don’t exist in the universe’s dynamics” (like taking both boxes and receiving $1,001,000) and “outcomes that can’t exist in my branch” (like there not being a bomb in the unlucky case). Because if you’re operating just in the branch you find yourself in, many outcomes whose probability an FDT agent is trying to affect are impossible from the problem specification (once you include observations).
And, to be clear, I do think agents “should” try to achieve outcomes that are impossible from the problem specification including observations, if certain criteria are met, in a way that basically lines up with FDT, just like agents “should” try to achieve outcomes that are already known to have happened from the problem specification including observations.
As an example, if you’re in Parfit’s Hitchhiker, you should pay once you reach town, even though reaching town has probability 1 in cases where you’re deciding whether or not to pay, and the reason for this is because it was necessary for reaching town to have had probability 1.
I think you need to make a clearer distinction here between “outcomes that don’t exist in the universe’s dynamics” (like taking both boxes and receiving $1,001,000) and “outcomes that can’t exist in my branch” (like there not being a bomb in the unlucky case). Because if you’re operating just in the branch you find yourself in, many outcomes whose probability an FDT agent is trying to affect are impossible from the problem specification (once you include observations).
And, to be clear, I do think agents “should” try to achieve outcomes that are impossible from the problem specification including observations, if certain criteria are met, in a way that basically lines up with FDT, just like agents “should” try to achieve outcomes that are already known to have happened from the problem specification including observations.
As an example, if you’re in Parfit’s Hitchhiker, you should pay once you reach town, even though reaching town has probability 1 in cases where you’re deciding whether or not to pay, and the reason for this is because it was necessary for reaching town to have had probability 1.
+1, I agree with all this.