[concept.equiv]

# 18 Concepts library [[concepts]](./#concepts)

## 18.7 Callable concepts [[concepts.callable]](concepts.callable#concept.equiv)

### 18.7.6 Concept equivalence_relation [concept.equiv]

[ð](#concept:equivalence_relation)

`template<class R, class T, class U>
  concept [equivalence_relation](#concept:equivalence_relation "18.7.6 Concept equivalence_­relation [concept.equiv]") = [relation](concept.relation#concept:relation "18.7.5 Concept relation [concept.relation]")<R, T, U>;
`

[1](#1)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/concepts.tex#L1290)

A [relation](concept.relation#concept:relation "18.7.5 Concept relation [concept.relation]") models [equivalence_relation](#concept:equivalence_relation "18.7.6 Concept equivalence_­relation [concept.equiv]") only if
it imposes an equivalence relation on its arguments[.](#1.sentence-1)
