=====Partially ordered monoids===== Abbreviation: **PoMon** ====Definition==== A \emph{partially ordered monoid} is a structure $\mathbf{A}=\langle A,\cdot,1,\le\rangle$ such that $\langle A,\cdot,1\rangle$ is a [[monoid]] $\langle G,\le\rangle$ is a [[partially ordered set]] $\cdot$ is \emph{orderpreserving}: $x\le y\Longrightarrow wxz\le wyz$ ==Morphisms== Let $\mathbf{A}$ and $\mathbf{B}$ be partially ordered monoids. A morphism from $\mathbf{A}$ to $\mathbf{B}$ is a function $h:A\rightarrow B$ that is an orderpreserving homomorphism: $h(x \cdot y)=h(x) \cdot h(y)$, $h(1)=1$, $x\le y\Longrightarrow h(x)\le h(y)$ ====Examples==== Example 1: ====Basic results==== Every monoid with the discrete partial order is a po-monoid. ====Properties==== ^[[Classtype]] |quasivariety | ^[[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==== $\begin{array}{lr} f(1)= &1\\ f(2)= &4\\ f(3)= &37\\ f(4)= &549\\ f(5)= &\\ \end{array}$ ====Subclasses==== [[Commutative partially ordered monoids]] [[Lattice-ordered monoids]] expanded type ====Superclasses==== [[Partially ordered semigroups]] reduced type ====References==== [(Lastname19xx> F. Lastname, \emph{Title}, Journal, \textbf{1}, 23--45 [[MRreview]] )]