ABSTRACT

An Introduction to Universal Artificial Intelligence provides the formal underpinning of what it means for an agent to act intelligently in an unknown environment. First presented in Universal Algorithmic Intelligence (Hutter, 2000), UAI offers a framework in which virtually all AI problems can be formulated, and a theory of how to solve them. UAI unifies ideas from sequential decision theory, Bayesian inference, and algorithmic information theory to construct AIXI, an optimal reinforcement learning agent that learns to act optimally in unknown environments. AIXI is the theoretical gold standard for intelligent behavior.

The book covers both the theoretical and practical aspects of UAI. Bayesian updating can be done efficiently with context tree weighting, and planning can be approximated by sampling with Monte Carlo tree search. It provides algorithms for the reader to implement, and experimental results to compare against. These algorithms are used to approximate AIXI. The book ends with a philosophical discussion of Artificial General Intelligence: Can super-intelligent agents even be constructed? Is it inevitable that they will be constructed, and what are the potential consequences?

This text is suitable for late undergraduate students. It provides an extensive chapter to fill in the required mathematics, probability, information, and computability theory background.

part I|122 pages

Introduction & Background

chapter 2Chapter 1|14 pages

Introduction

chapter Chapter 2|106 pages

Background

part II|90 pages

Algorithmic Prediction

chapter 124Chapter 3|32 pages

Bayesian Sequence Prediction

chapter Chapter 4|42 pages

The Context Tree Weighting Algorithm

chapter Chapter 5|14 pages

Variations on CTW

part III|92 pages

A Family of Universal Agents

chapter 214Chapter 6|20 pages

Agency

chapter Chapter 7|16 pages

Universal Artificial Intelligence

chapter Chapter 8|16 pages

Optimality of Universal Agents

chapter Chapter 9|18 pages

Other Universal Agents

chapter Chapter 10|20 pages

Multi-Agent Setting

part IV|56 pages

Approximating Universal Agents

chapter 306Chapter 11|8 pages

AIXI-MDP

chapter Chapter 12|36 pages

Monte Carlo AIXI with Context Tree Weighting

chapter Chapter 13|10 pages

Computational Aspects

part V|22 pages

Alternative Approaches

chapter 362Chapter 14|20 pages

Feature Reinforcement Learning

part VI|58 pages

Safety and Discussion

chapter 384Chapter 15|28 pages

ASI Safety

chapter Chapter 16|28 pages

Philosophy of AI