# ideal

> in order theory, a nonempty, upward‐directed, downward‐closed subset of a preordered set

**Wikidata**: [Q1656686](https://www.wikidata.org/wiki/Q1656686)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/Ideal_(order_theory))  
**Source**: https://4ort.xyz/entity/ideal-q1656686


## References

1. Freebase Data Dumps. 2013