# Duffin–Schaeffer theorem

> theorem in metric number theory

**Wikidata**: [Q5312375](https://www.wikidata.org/wiki/Q5312375)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/Duffin–Schaeffer_theorem)  
**Source**: https://4ort.xyz/entity/duffin-schaeffer-theorem