---
tag: 0VABYWJWH9
kind: concept
name: Preorder
aliases: [quasiorder]
msc: [06A06]
sources:
  - url: https://en.wikipedia.org/wiki/Preorder
    locator: lead section
same_as:
  wikidata: Q1425985
  wikipedia: Preorder
---

## Summary

A preorder is a relation that is reflexive and transitive.
It compares elements, but two different elements can be equivalent under it.