I have been thinking about this same mathematical object (although with a different orientation/motivation) as where I want to go with a weaker replacement for utility functions.
I get the impression that for Diffractor/Vanessa, the heart of a concave-value-function-on-lotteries is that it represents the worst case utility over some set of possible utility functions. For me, on the other hand, a concave value function represents the capacity for compromise -- if I get at least half the good if I get what I want with 50% probability, then I have the capacity...
Then it is equivalent to the thing I call B2 in edit 2 in the post (Assuming A1-A3).
In this case, your modified B2 is my B2, and your B3 is my A4, which follows from A5 assuming A1-A3 and B2, so your suspicion that these imply C4 is stronger than my Q6, which is false, as I argue here.
However, without A5, it is actually much easier to see that this doesn't work. The counterexample here satisfies my A1-A3, your weaker version of B2, your B3, and violates C4.
Your B3 is equivalent to A4 (assuming A1-3).
Your B2 is going to rule out a bunch of concave functions. I was hoping to only use axioms consistent with all (continuous) concave functions.
I am skeptical that it will be possible to salvage any nice VNM-like theorem here that makes it all the way to concavity. It seems like the jump necessary to fix this counterexample will be hard to express in terms of only a preference relation.
The answers to Q3, Q4 and Q6 are all no. I will give a sketchy argument here.
Consider the one dimensional case, where the lotteries are represented by real numbers in the interval , and consider the function given by . Let be the preference order given by if and only if .
is continuous and quasi-concave, which means is going to satisfy A1, A2, A3, A4, and B2. Further, since is monotonically increasing up to the unique argmax, and ...
You can also think of A5 in terms of its contrapositive: For all , if , then for all
This is basically just the strict version of A4. I probably should have written it that way instead. I wanted to use instead of , because it is closer to the base definition, but that is not how I was natively thinking about it, and I probably should have written it the way I think about it.
Alex's counterexample as stated is not a counterexample to Q4, since it is in fact concave.
I believe your counterexample violates A5, taking , , and .
That does not rule out your counterexample. The condition is never met in your counterexample.
The answer to Q1 is no, using the same counter example here. However, the spirit of my original question lives on in Q4 (and Q6).
Claim: A1, A2, A3, A5, and B2 imply A4.
Proof: Assume we have a preference ordering that satisfies A1, A2, A3, A5, and B2, and consider lotteries , and , with . Let . It suffices to show . Assume not, for the purpose of contradiction. Then (by axiom A1), . Thus by axiom B2 there exists a such that . By axiom A3, we may assume for some . Observe that where . is positive, since otherwise...
Oh, nvm, that is fine, maybe it works.
Oh, no, I made a mistake, this counterexample violates A3. However, the proposed fix still doesn't work, because you just need a function that is decreasing in probability of , but does not hit 0, and then jumps to 0 when probability of is 1.
I haven't actually thought about whether A5 implies A4 though. It is plausible that it does. (together with A1-A3, or some other simple axioms,)
When , we get A4 from A5, so it suffices to replace A4 with the special case that . If , and , a mixture of and , then all we need to do is have any Y such that , then we can get between and by A3, and then will also be a mixture of and , contradicting A5, since .
A1,A2,A3,A5 do ...
(and everywhere you say "good" and "bad", they are the non-strict versions of the words)
Your understanding of A4 is right. In A5, "good" should be replaced with "bad."
You have the inequality backwards. You can't apply A5 when the mixture is better than the endpoint, only when the mixture is worse than the endpoint.
That proposed axiom to add does not work. Consider the function on lotteries over that gives utility 1 if is supported, and otherwise gives utility equality to the probability of . This function is concave but not continuous, satisfies A1-A5 and the extra axiom I just proposed, and cannot be made continuous.
I edited the post to remove the continuity assumption from the main conclusion. However, my guess is that if we get a VNM-like result, we will want to add back in another axiom that gives us continuity,
I meant the conclusions to all be adding to the previous one, so this actually also answers the main question I stated, by violating continuity, but not the main question I care about. I will edit the post to say that I actually care about concavity, even without continuity.
Nice! This, of course, seems like something we should salvage, by e.g. adding an axiom that if A is strictly preferred to B, there should be a lottery strictly between them.
To see why A1-A4 is not enough to prove C4 on its own, consider the preference relation on the space of lotteries between two outcomes X and Y such that all lotteries are equivalent if , and if , higher values of are preferred. This satisfies A1-A4, but cannot be expressed with a concave function, since we would have to have , contradicting concavity. We can, however express it with a quasi-concave function: .
I believe using A4 (and maybe also A5) in multiple places will be important to proving a positive result. This is because A1, A2, and A3 are extremely week on their own.
A1-A3 is not even enough to prove C1. To see a counterexample, take any well ordering on , and consider the preference ordering over the space of lotteries on a two element set of deterministic outcomes. If two lotteries have probabilities of the first outcome that differ by a rational number, they are equivalent, otherwise, you compare them according to your well ordering. Th...
I believe this post is (for the most part) accurate and demonstrates understanding of what is going on with logical induction. Thanks for writing (and coding) it!
I think your numbers are wrong, and the right column on the output should say 20% 20% 20%.
The output actually agrees with each of the components on every event in that component's sigma algebra. The input distributions don't actually have any conflicting beliefs, and so of course the output chooses a distribution that doesn't disagree with either.
I agree that the 0s are a bit unfortunate.
I think the best way to think of the type of the object you get out is not a probability distribution on but what I am calling a partial probability distribut...
Yeah, remember the above is all for updateless agents, which are already computationally intractable. For updateful agents, we will want to talk about conditional counterfactability. For example, if you and I are in a prisoners dilemma, we could would conditional on all the stuff that happened prior to us being put in separate cells, and given this condition, the histories are much smaller.
Also, we could do all of our reasoning up to a high level world model that makes histories more reasonably sized.
Also, if we could think of counterfactability as a...
I agree, this is why I said I am being sloppy with conflating the output and our understanding of the output. We want our understanding of the output to screen off the history.
I mean, the definition is a little vague. If your meaning is something like "It goes in A if it is more accurately described as controlled by the viscera, and it goes in P if it is more accurately described as controlled by the environment," then I guess you can get a bijection by definition, but it is not obvious these are natural categories. I think there will be parts of the boundary that feel like they are controlled by both or neither, depending on how strictly you mean "controlled by."
My default plan is to not try to rename Cartesian frames, mostly because the benefit seems small, and I care more about building up the FFS ontology over the Cartesian frame one.
I agree completely. I am not really happy with any of the language in this post, and I want it to have scope limited to this post. I will for the most part say boundary for both the additive and multiplicative variants.
To be clear, everywhere I say “is wrong,” I mean I wish the model is slightly different, not that anything is actually is mistaken. In most cases, I don’t really have much of an idea how to actually implement my recommendation.
Forcing the AxP bijection is an interesting idea, but it feels a little too approximate to my taste.
Oh yeah, oops, that is what it says. Wasn’t careful, and was responding to reading an old draft. I agree that the post is already saying roughly what I want there. Instead, I should have said that the B=AxP bijection is especially unrealistic. Sorry.
Overall, this is my favorite thing I have read on lesswrong in the last year.
Agreements:
I agree very strongly with most of this post, both in the way you are thinking about boundaries, and in the scale and scope of applications of boundaries to important problems.
In particular on the applications, I think that boundaries as you are defining them are crucial to developing decision theory and bargaining theory (and indeed are already helpful for thinking about bargaining and fairness in real life), but I also agree with your other potential applications.
I pa...
Note that I wrote this post a month ago, while seeing an earlier draft of the sequence post 3a (before active/passive distinction was central) and was waiting to post it until after that post. I am posting it now unedited, so some of the thoughts here might be outdated. In particular, I think this post does not respect enough the sense in which the FFS ontology is wrong in that it does not have space for expressing the direction of entanglement.
I mostly agree with this post.
Figuring out the True Name of a thing, a mathematical formulation sufficiently precise that one can apply lots of optimization pressure without the formulation breaking down, is absolutely possible and does happen.
Precision feels pretty far from the true name of the important feature of true names, I am not quite sure what precision means, but on one definition, precision is the opposite of generality, and true names seem anti-precise. I am not saying precision is not a virtue, and it does seem like precision is involved. (lik...
I agree with this asymmetry.
One thing I am confused about is whether to think of the e-coli as qualitatively different from the human. The e-coli is taking actions that can be well modeled by an optimization process searching for actions that would be good if this optimization process output them, which has some reflection in it.
It feels like it can behaviorally be well modeled this way, but is mechanistically not shaped like this, I feel like the mechanistic fact is more important, but I feel like we are much closer to having behavioral definitions of agency than mechanistic ones.
Which isn't *that* large an update. The average number of agent foundations researchers (That are public facing enough that you can update on their lack of progress) at MIRI over the last decade is like 4.
Figuring out how to factor in researcher quality is hard, but it seems plausible to me that the amount of quality adjusted attention directed at your subgoal over the next decade is significantly larger than the amount of attention directed at your subgoal over the last decade. (Which would not all come from you. I do think that Agent Foundations today is...
To operationalize, I claim that MIRI has been directed at a close enough target to yours that you probably should update on MIRI's lack of progress at least as much as you would if MIRI was doing the same thing as you, but for half as long.
Which isn't *that* large an update. The average number of agent foundations researchers (That are public facing enough that you can update on their lack of progress) at MIRI over the last decade is like 4.
Figuring out how to factor in researcher quality is hard, but it seems plausible to me that the amount of quality adjusted attention directed at your subgoal over the next decade is significantly larger than the amount of attention directed at your subgoal over the last decade. (Which would not all come from you. I do think that Agent Foundations today is...
Hmm, yeah, we might disagree about how much reflection(self-reference) is a central part of agency in general.
It seems plausible that it is important to distinguish between the e-coli and the human along a reflection axis (or even more so, distinguish between evolution and a human). Then maybe you are more focused on the general class of agents, and MIRI is more focused on the more specific class of "reflective agents."
Then, there is the question of whether reflection is going to be a central part of the path to (F/D)OOM.
Does this seem right to you?
To operationalize, I claim that MIRI has been directed at a close enough target to yours that you probably should update on MIRI's lack of progress at least as much as you would if MIRI was doing the same thing as you, but for half as long.
I want to disagree about MIRI.
Mostly, I think that MIRI (or at least a significant subset of MIRI) has always been primarily directed at agenty systems in general.
I want to separate agent foundations at MIRI into three eras. The Eliezer Era (2001-2013), the Benya Era (2014-2016), and the Scott Era(2017-).
The transitions between eras had an almost complete overhaul of the people involved. In spite of this, I believe that they have roughly all been directed at the same thing, and that John is directed at the same thing.
The proposed mechanism behi...
I generally agree with most of this, but I think it misses the main claim I wanted to make. I totally agree that all three eras of MIRI's agent foundations research had some vision of the general theory of agency behind them, driving things. My point of disagreement is that, for most of MIRI's history, elucidating that general theory has not been the primary optimization objective.
Let's go through some examples.
The Sequences: we can definitely see Eliezer's understanding of the general theory of agency in many places, especially when talking about Bayes an...
Note that the title is misleading. This is really countable dimension factored spaces, which is much better, since it allows for the possibility of something kind of like continuous time, where between any two points in time, you can specify a time strictly between them.
Fixed, Thanks.
Yeah, also note that the history of given is not actually a well defined concept. There is only the history of given for . You could define it to be the union of all of those, but that would not actually be used in the definition of orthogonality. In this case , , and are all independent of choice of , but in general, you should be careful about that.
I think that works, I didn't look very hard. Yore histories of X given Y and V given Y are wrong, but it doesn't change the conclusion.
I could do that. I think it wouldn't be useful, and wouldn't generalize to sub partitions.
I don't know, the negation of the first thing? A system that can freely model humans, or at least perform computation indistinguishable from modeling humans.
Here are the most interesting things about these objects to me that I think this post does not capture.
Given a distribution over non-negative non-identically-zero infrafunctions, up to a positive scalar multiple, the pointwise geometric expectation exists, and is an infra function (up to a positive scalar multiple).
(I am not going to give all the math and be careful here, but hopefully this comment will provide enough of a pointer if someone wants to investigate this.)
This is a bit of a miracle. Compare this with arithmetic expectation of utility fun... (read more)