=====Ordered monoids with zero===== Abbreviation: **OMonZ** ====Definition==== An \emph{ordered monoid with zero} is of the form $\mathbf{A}=\langle A,\cdot,1,0,\le\rangle$ such that $\mathbf{A}=\langle A,\cdot,1,\le\rangle$ is an [[ordered monoid]] and $0$ is a \emph{zero}: $x\cdot 0 = 0$ and $0\cdot x = 0$ ==Morphisms== Let $\mathbf{A}$ and $\mathbf{B}$ be ordered monoids. A morphism from $\mathbf{A}$ to $\mathbf{B}$ is a function $h:A\rightarrow B$ that is a orderpreserving homomorphism: $h(x \cdot y)=h(x) \cdot h(y)$, $h(1)=1$, $h(0)=0$, $x\le y\Longrightarrow h(x)\le h(y)$. ====Examples==== Example 1: ====Basic results==== ====Properties==== Feel free to add or delete properties from this list. The list below may contain properties that are not relevant to the class that is being described. ^[[Classtype]] |universal | ^[[Equational theory]] | | ^[[Quasiequational theory]] | | ^[[First-order theory]] | | ^[[Locally finite]] | | ^[[Residual size]] | | ^[[Congruence distributive]] | | ^[[Congruence modular]] | | ^[[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==== $f(n)=$ number of members of size $n$. $\begin{array}{lr} f(1)= &1\\ f(2)= &1\\ f(3)= &3\\ f(4)= &15\\ f(5)= &84\\ f(6)= &575\\ f(7)= &4687\\ f(8)= &45223\\ f(9)= &\\ \end{array}$ ====Subclasses==== [[Commutative ordered monoids]] ====Superclasses==== [[Ordered monoids]] reduced type [[Ordered semigroups with zero]] reduced type [[Representable residuated lattices]] ====References==== [(Lastname19xx> F. Lastname, \emph{Title}, Journal, \textbf{1}, 23--45 [[MRreview]] )]