# Alexander horned sphere

> topological embedding of a 2-dimensional sphere in 3-space whose interior is a 3-ball but whose exterior is not simply connected

**Wikidata**: [Q1361755](https://www.wikidata.org/wiki/Q1361755)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/Alexander_horned_sphere)  
**Source**: https://4ort.xyz/entity/alexander-horned-sphere


## References

1. Freebase Data Dumps. 2013