# Hall's marriage theorem

> theorem that a finite bipartite graph has a perfect matching iff any subset of vertices from one group has a neighbourhood of equal or greater size

**Wikidata**: [Q536640](https://www.wikidata.org/wiki/Q536640)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/Hall's_marriage_theorem)  
**Source**: https://4ort.xyz/entity/hall-s-marriage-theorem


## References

1. Freebase Data Dumps. 2013