---
tag: 0QAJHFGZZJ
kind: concept
name: Uniqueness quantifier
aliases: [unique-existential-quantifier, uniqueness-quantification]
msc: [03B10]
sources:
  - url: https://en.wikipedia.org/wiki/Uniqueness_quantification
    locator: lead section
same_as:
  wikidata: Q2502253
  wikipedia: Uniqueness quantification
---

## Summary

The uniqueness quantifier $\exists!$ expresses "there exists exactly one".