 Universally Baire set

In the context of set theory and descriptive set theory, a **Universally Baire set** is a type of subset of a Polish space (a separable completely metrizable topological space) that has certain properties concerning measure and category. Here's a more precise description: 1. **Baire Space**: A topological space is a Baire space if the intersection of countably many dense open sets is dense. This property is significant in various areas of analysis and topology.