1.An Untrollable Mathematician
post by Abram Demski 538 days ago | Alex Appel, Sam Eisenstat, Vanessa Kosoy, Jack Gallagher, Jessica Taylor, Paul Christiano, Scott Garrabrant and Vladimir Slepnev like this | 1 comment

Follow-up to All Mathematicians are Trollable.

It is relatively easy to see that no computable Bayesian prior on logic can converge to a single coherent probability distribution as we update it on logical statements. Furthermore, the non-convergence behavior is about as bad as could be: someone selecting the ordering of provable statements to update on can drive the Bayesian’s beliefs arbitrarily up or down, arbitrarily many times, despite only saying true things. I called this wild non-convergence behavior “trollability”. Previously, I showed that if the Bayesian updates on the provabilily of a sentence rather than updating on the sentence itself, it is still trollable. I left open the question of whether some other side information could save us. Sam Eisenstat has closed this question, providing a simple logical prior and a way of doing a Bayesian update on it which (1) cannot be trolled, and (2) converges to a coherent distribution.

 2. Where does ADT Go Wrong? discussion post by Abram Demski 605 days ago | Jack Gallagher and Jessica Taylor like this | 1 comment
 3. An Approach to Logically Updateless Decisions discussion post by Abram Demski 786 days ago | Sam Eisenstat, Jack Gallagher and Scott Garrabrant like this | 4 comments
 4. Index of some decision theory posts discussion post by Tsvi Benson-Tilsen 1012 days ago | Ryan Carey, Jack Gallagher, Jessica Taylor and Scott Garrabrant like this | discuss
5.Logical Inductors that trust their limits
post by Scott Garrabrant 1028 days ago | Jack Gallagher, Jessica Taylor and Patrick LaVictoire like this | 2 comments

Here is another open question related to Logical Inductors. I have not thought about it very long, so it might be easy.

Does there exist a logical inductor $$\{\mathbb P_n\}$$ over PA such that for all $$\phi$$:

1. PA proves that $$\mathbb P_\infty(\phi)$$ exists and is in $$[0,1]$$, and

2. $$\mathbb{E}_n(\mathbb{P}_\infty(\phi))\eqsim_n\mathbb{P}_n(\phi)$$?

6.Universal Inductors
post by Scott Garrabrant 1035 days ago | Sam Eisenstat, Jack Gallagher, Benja Fallenstein, Jessica Taylor, Patrick LaVictoire and Tsvi Benson-Tilsen like this | discuss

Now that the Logical Induction paper is out, I am directing my attention towards decision theory. The approach I currently think will be most fruitful is attempting to make a logically updateless version of Wei Dai’s Updateless Decision Theory. Abram Demski has posted on here about this, but I think Logical Induction provides a new angle with which we can attack the problem. This post will present an alternate way of viewing Logical Induction which I think will be especially helpful for building a logical UDT. (The Logical Induction paper is a prerequisite for this post.)

### NEW DISCUSSION POSTS

[Note: This comment is three
 by Ryan Carey on A brief note on factoring out certain variables | 0 likes

There should be a chat icon
 by Alex Mennen on Meta: IAFF vs LessWrong | 0 likes

Apparently "You must be
 by Jessica Taylor on Meta: IAFF vs LessWrong | 1 like

There is a replacement for
 by Alex Mennen on Meta: IAFF vs LessWrong | 1 like

Regarding the physical
 by Vanessa Kosoy on The Learning-Theoretic AI Alignment Research Agend... | 0 likes

I think that we should expect
 by Vanessa Kosoy on The Learning-Theoretic AI Alignment Research Agend... | 0 likes

I think I understand your
 by Jessica Taylor on The Learning-Theoretic AI Alignment Research Agend... | 0 likes

This seems like a hack. The
 by Jessica Taylor on The Learning-Theoretic AI Alignment Research Agend... | 0 likes

After thinking some more,
 by Vanessa Kosoy on The Learning-Theoretic AI Alignment Research Agend... | 0 likes

Yes, I think that we're
 by Vanessa Kosoy on The Learning-Theoretic AI Alignment Research Agend... | 0 likes

My intuition is that it must
 by Vanessa Kosoy on The Learning-Theoretic AI Alignment Research Agend... | 0 likes

To first approximation, a
 by Vanessa Kosoy on The Learning-Theoretic AI Alignment Research Agend... | 0 likes

Actually, I *am* including
 by Vanessa Kosoy on The Learning-Theoretic AI Alignment Research Agend... | 0 likes

Yeah, when I went back and
 by Alex Appel on Optimal and Causal Counterfactual Worlds | 0 likes

> Well, we could give up on
 by Jessica Taylor on The Learning-Theoretic AI Alignment Research Agend... | 0 likes