This is an introduction to a new way of thinking about time, based on finite factored sets.

A factored set is a set understood as a Cartesian product, in the same sense that a partition is a way to understand a set as a disjoint union.

This sequence begins by applying finite factored sets to temporal inference, showing some advantages of this framework over Judea Pearl’s theory of causal inference. Finite factored sets have many potential applications outside of temporal inference, however, and future writing will explore embedded agency and other topics through the lens of finite factored sets.

The “Details and Proofs” section of this sequence is also available as an arXiv paper: “Temporal Inference with Finite Factored Sets.”