# Borel hierarchy

> Mathematical logic hierarchy

**Wikidata**: [Q893487](https://www.wikidata.org/wiki/Q893487)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/Borel_hierarchy)  
**Source**: https://4ort.xyz/entity/borel-hierarchy


## References

1. [OpenAlex](https://docs.openalex.org/download-snapshot/snapshot-data-format)