# Fundamental lemma of Langlands and Shelstad

> theorem relating orbital integrals on a reductive group over a local field to stable orbital integrals on its endoscopic groups, conjectured by Langlands and proven by Ngô

**Wikidata**: [Q57510](https://www.wikidata.org/wiki/Q57510)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/Fundamental_lemma_(Langlands_program))  
**Source**: https://4ort.xyz/entity/fundamental-lemma-of-langlands-and-shelstad