---
tag: 0BJR9QR08E
kind: concept
name: Subset
aliases: [inclusion, superset, proper-subset]
msc: ["03E20"]
sources:
  - url: https://en.wikipedia.org/wiki/Subset
    locator: lead section
same_as:
  wikidata: Q177646
  wikipedia: Subset
---

## Summary

A set $A$ is a subset of a set $B$ when each element of $A$ is an element of $B$.