# Schur's lemma

> lemma stating that a module homomorphism between two simple modules over the same ring is either an isomorphism or identically zero

**Wikidata**: [Q1816952](https://www.wikidata.org/wiki/Q1816952)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/Schur's_lemma)  
**Source**: https://4ort.xyz/entity/schur-s-lemma


## References

1. Freebase Data Dumps. 2013
2. [OpenAlex](https://docs.openalex.org/download-snapshot/snapshot-data-format)