# Bijectivity and unique preimages

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)



## [Bijectivity and unique preimages](https://ocme.evemisslab.com/en/atlas/atlas-bijective/)

A bijection is both injective and surjective; equivalently, every codomain element has exactly one permitted preimage.

atlas-bijective · canonical_mko

[Bijectivity and unique preimages](https://ocme.evemisslab.com/en/mko/mko-bijective/)

## Prerequisite nodes


- [Injectivity and distinct inputs](https://ocme.evemisslab.com/en/atlas/atlas-injective/)
- [Surjectivity and codomain coverage](https://ocme.evemisslab.com/en/atlas/atlas-surjective/)