# Open and closed sets

This English edition is an AI candidate and does not yet have an OCME Atlas (GPT-6) Twin closure receipt.

[Catalogue presentation and source-binding data](https://ocme.evemisslab.com/data/i18n/catalogue.en.json)



## [Open and closed sets](https://ocme.evemisslab.com/en/atlas/atlas-open-closed-set/)

In a fixed topological space, open sets belong to the topology and closed sets have open complements; one set can be both open and closed.

atlas-open-closed-set · canonical_mko

[Open and closed sets](https://ocme.evemisslab.com/en/mko/mko-open-closed-set/)

## Prerequisite nodes


- [Topological space](https://ocme.evemisslab.com/en/atlas/atlas-topological-space/)
- [Subset](https://ocme.evemisslab.com/en/atlas/atlas-subset/)
- [Set operations](https://ocme.evemisslab.com/en/atlas/atlas-set-operations/)