---
tag: T07RRJ3AHF
kind: concept
name: First
sources:
  - wikipedia: en:43580500@r1360947732
    locator: Glossary of set theory, section F
    note: adopted
    mention: wikipedia://en/43580500#S3W1
    sections: [Summary]
inventory: [ZJ765GTSR2]
---

## Summary

A set of [[first category|0FQPYAY9PJ]] is the same as a meager set: one that is the union of a countable number of nowhere-dense sets.

An ordinal of the first class is a finite ordinal

An ordinal of the first kind is a successor ordinal

[[First-order logic|086QKPF0A6]] allows quantification over elements of a model, but not over subsets