# Regular expression

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)



## [Regular expression](https://ocme.evemisslab.com/en/atlas/atlas-regular-expression/)

Regular expressions recursively build languages from the empty language, epsilon, alphabet symbols, union, concatenation and Kleene star.

atlas-regular-expression · canonical_mko

[Regular expression](https://ocme.evemisslab.com/en/mko/mko-regular-expression/)

## Prerequisite nodes


- [Regular language](https://ocme.evemisslab.com/en/atlas/atlas-regular-language/)
- [Set](https://ocme.evemisslab.com/en/atlas/atlas-set/)
- [Sequence](https://ocme.evemisslab.com/en/atlas/atlas-sequence/)
- [Mathematical induction](https://ocme.evemisslab.com/en/atlas/atlas-mathematical-induction/)