=====Idempotent semirings=====

Abbreviation: **ISRng**
====Definition====
An \emph{idempotent semiring} is a semiring $\mathbf{S}=\langle S,\vee
,\cdot \rangle $ such that


$\vee $ is idempotent:  $x\vee x=x$

==Morphisms==
Let $\mathbf{S}$ and $\mathbf{T}$ be idempotent semirings. A morphism from $\mathbf{S}$ to $\mathbf{T}$ is a function $h:S\to T$ that is a
homomorphism: 

$h(x\vee y)=h(x)\vee h(y)$, $h(x\cdot y)=h(x)\cdot h(y)$

====Examples====
Example 1: 

====Basic results====

====Properties====
^[[Classtype]]  |Variety |
^[[Equational theory]]  |Decidable |
^[[Quasiequational theory]]  | |
^[[First-order theory]]  |Undecidable |
^[[Locally finite]]  |No |
^[[Residual size]]  |Unbounded |
^[[Congruence distributive]]  |No |
^[[Congruence modular]]  |No |
^[[Congruence n-permutable]]  | |
^[[Congruence regular]]  | |
^[[Congruence uniform]]  | |
^[[Congruence extension property]]  | |
^[[Definable principal congruences]]  | |
^[[Equationally def. pr. cong.]]  | |
^[[Amalgamation property]]  | |
^[[Strong amalgamation property]]  | |
^[[Epimorphisms are surjective]]  | |
====Finite members====

$\begin{array}{lr}
f(1)= &1\\
f(2)= &6\\
f(3)= &61\\
f(4)= &866\\
f(5)= &\\
f(6)= &\\
\end{array}$

====Subclasses====
[[Idempotent semirings with identity]] 

[[Idempotent semirings with zero]] 

====Superclasses====
[[Semirings]] 


====References====

[(Ln19xx>
)]