# At-most-countable set

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)



## [At-most-countable set](https://ocme.evemisslab.com/en/atlas/atlas-at-most-countable-set/)

A set is at most countable if it is finite or has an explicit injection into the natural numbers; this is not the same as countably infinite.

atlas-at-most-countable-set · canonical_mko

[At-most-countable set](https://ocme.evemisslab.com/en/mko/mko-at-most-countable-set/)

## Prerequisite nodes


- [Cardinality comparison of sets](https://ocme.evemisslab.com/en/atlas/atlas-cardinality-comparison/)
- [Natural number](https://ocme.evemisslab.com/en/atlas/atlas-natural-number/)
- [Injectivity and distinct inputs](https://ocme.evemisslab.com/en/atlas/atlas-injective/)
- [Surjectivity and codomain coverage](https://ocme.evemisslab.com/en/atlas/atlas-surjective/)