# Maximal ideal
A (two-sided) proper [[ideal]] $I \triangleleft R$ is called a **maximal ideal** iff whenever $J \trianglelefteq R$ is an [[ideal]] such that $I \trianglelefteq J \trianglelefteq R$,
then either $I = J$ or $J = R$. #m/def/ring
$$
\begin{align*}
I \trianglelefteq J \trianglelefteq R \iff [I = J] \lor [J = R]
\end{align*}
$$
Maximal ideal generalizes [[Irreducible element]] in the same way that [[Prime ideal]] generalized [[Prime element]].
## Properties
- [[A maximal ideal in a commutative ring is prime]]
- [[Condition for a quotient commutative ring to be a field]]
- [[Every commutative ring has a maximal ideal]]
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#state/tidy | #lang/en | #SemBr