---
tag: S19G8ZP707
kind: concept
name: Monus
aliases: [limited-subtraction, m-semiring, naturally-ordered, naturally-ordered-monoid, naturally-ordered-semiring, proper-subtraction, subtraction-of-natural-numbers, truncated-subtraction]
sources:
  - wikipedia: en:22395202@r1329642033
    locator: Monus
    note: adopted
    mention: wikipedia://en/22395202
    sections: [Summary]
same_as:
  wikidata: Q6906971
  wikipedia: Monus
inventory: [5S7W2KEMPZ]
---

## Summary

In mathematics, **monus** is an operator on certain [[commutative|099E72KTF8]] [[monoids|0N6R902FG1]] that are not groups. A commutative monoid on which a monus operator is defined is called a **commutative monoid with monus**, or **CMM**. The monus operator may be denoted with the minus sign, "$-$", because the [[natural numbers|0MWKJ44V5A]] are a CMM under subtraction. It is also denoted with a dotted minus sign, "$\mathbin{\dot{-}}$", to distinguish it from the standard subtraction operator.