LessWrong (30+ Karma)

“Crisp Supra-Decision Processes” by Brittany Gelb


Listen Later

Audio note: this article contains 363 uses of latex notation, so the narration may be difficult to follow. There's a link to the original text in the episode description.

Introduction

In this post, we describe a generalization of Markov decision processes (MDPs) and partially observable Markov decision processes (POMDPs) called crisp supra-MDPs and supra-POMDPs. The new feature of these decision processes is that the stochastic transition dynamics are multivalued, i.e. specified by credal sets. We describe how supra-MDPs give rise to crisp causal laws, the hypotheses of infra-Bayesian reinforcement learning. Furthermore, we discuss how supra-MDPs can approximate MDPs by a coarsening of the state space. This coarsening allows an agent to be agnostic about the detailed dynamics while still having performance guarantees for the full MDP.

Analogously to the classical theory, we describe an algorithm to compute a Markov optimal policy for supra-MDPs with finite time [...]

---

Outline:

(00:22) Introduction

(01:41) Supra-Markov Decision Processes

(01:45) Defining supra-MDPs

(06:55) Supra-bandits

(08:02) Crisp causal laws arising from supra-MDPs and (supra-)RDPs

(19:25) Approximating an MDP with a supra-MDP

(22:42) Computing the Markov optimal policy for finite time horizons

(25:02) Existence of stationary optimal policy

(28:18) Interpreting supra-MDPs as stochastic games

(32:40) Regret bounds for episodic supra-MDPs

(34:16) Supra-Partially Observable Markov Decision Processes

(36:16) Equivalence of crisp causal laws and crisp supra-POMDPs

(37:18) Proof of Proposition 2

(41:21) Acknowledgements

The original text contained 8 footnotes which were omitted from this narration.

---

First published:

September 17th, 2025

Source:

https://www.lesswrong.com/posts/mt82ZhdEsfh6CNYse/crisp-supra-decision-processes

---

Narrated by TYPE III AUDIO.

---

Images from the article:

__T3A_INLINE_LATEX_PLACEHOLDER___n___T3A_INLINE_LATEX_END_PLACEHOLDER__ for "do nothing." In some cases, the transition probabilities are precisely specified. In other cases, credal sets (notated here by intervals) over the two-element state space describe the transition probabilities." style="max-width: 100%;" />

Apple Podcasts and Spotify do not show images in the episode description. Try Pocket Casts, or another podcast app.

...more
View all episodesView all episodes
Download on the App Store

LessWrong (30+ Karma)By LessWrong


More shows like LessWrong (30+ Karma)

View all
Making Sense with Sam Harris by Sam Harris

Making Sense with Sam Harris

26,383 Listeners

Conversations with Tyler by Mercatus Center at George Mason University

Conversations with Tyler

2,423 Listeners

The Peter Attia Drive by Peter Attia, MD

The Peter Attia Drive

8,233 Listeners

Sean Carroll's Mindscape: Science, Society, Philosophy, Culture, Arts, and Ideas by Sean Carroll | Wondery

Sean Carroll's Mindscape: Science, Society, Philosophy, Culture, Arts, and Ideas

4,147 Listeners

ManifoldOne by Steve Hsu

ManifoldOne

92 Listeners

Your Undivided Attention by The Center for Humane Technology, Tristan Harris, Daniel Barcay and Aza Raskin

Your Undivided Attention

1,561 Listeners

All-In with Chamath, Jason, Sacks & Friedberg by All-In Podcast, LLC

All-In with Chamath, Jason, Sacks & Friedberg

9,829 Listeners

Machine Learning Street Talk (MLST) by Machine Learning Street Talk (MLST)

Machine Learning Street Talk (MLST)

89 Listeners

Dwarkesh Podcast by Dwarkesh Patel

Dwarkesh Podcast

489 Listeners

Hard Fork by The New York Times

Hard Fork

5,479 Listeners

The Ezra Klein Show by New York Times Opinion

The Ezra Klein Show

16,097 Listeners

Moonshots with Peter Diamandis by PHD Ventures

Moonshots with Peter Diamandis

532 Listeners

No Priors: Artificial Intelligence | Technology | Startups by Conviction

No Priors: Artificial Intelligence | Technology | Startups

133 Listeners

Latent Space: The AI Engineer Podcast by swyx + Alessio

Latent Space: The AI Engineer Podcast

97 Listeners

BG2Pod with Brad Gerstner and Bill Gurley by BG2Pod

BG2Pod with Brad Gerstner and Bill Gurley

509 Listeners