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distributive_lattice_ordered_semigroups [2010/07/29 15:46] (current)
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+=====Distributive lattice-ordered semigroups=====
+
+Abbreviation: **DLOS**
+
+====Definition====
+A \emph{distributive lattice ordered semigroup} is a structure $\mathbf{A}=\langle A,\vee,\wedge,\cdot\rangle$ of type $\langle 2,2,2\rangle$ such that
+
+$\langle A,\vee,\wedge\rangle$ is a [[distributive lattice]]
+
+$\langle A,\cdot\rangle$ is a [[semigroup]]
+
+$\cdot$ distributes over $\vee$:  $x\cdot(y\vee z)=(x\cdot y)\vee (x\cdot z)$ and $(x\vee y)\cdot z=(x\cdot z)\vee (y\cdot z)$
+
+Remark: This is a template.
+
+It is not unusual to give several (equivalent) definitions. Ideally, one of the definitions would give an irredundant axiomatization that does not refer to other classes.
+
+==Morphisms==
+Let $\mathbf{A}$ and $\mathbf{B}$ be distributive lattice-ordered semigroups. A morphism from $\mathbf{A}$ to $\mathbf{B}$ is a function $h:A\rightarrow B$ that is a homomorphism:
+$h(x\vee y)=h(x) \vee h(y)$,
+$h(x\wedge y)=h(x) \wedge h(y)$,
+$h(x\cdot y)=h(x) \cdot h(y)$
+
+====Definition====
+An \emph{...} is a structure $\mathbf{A}=\langle A,...\rangle$ of type $\langle +...\rangle$ such that
+
+$...$ is ...:  $axiom$
+
+$...$ is ...:  $axiom$
+
+====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]]                        |variety  |
+^[[Equational theory]]                | |
+^[[Quasiequational theory]]           | |
+^[[First-order theory]]               | |
+^[[Locally finite]]                   | |
+^[[Residual size]]                    | |
+^[[Congruence distributive]]          |yes |
+^[[Congruence modular]]               |yes |
+^[[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====
+
+$\begin{array}{lr} + f(1)= &1\\ + f(2)= &\\ + f(3)= &\\ + f(4)= &\\ + f(5)= &\\ +\end{array}$
+$\begin{array}{lr} + f(6)= &\\ + f(7)= &\\ + f(8)= &\\ + f(9)= &\\ + f(10)= &\\ +\end{array}$
+
+
+====Subclasses====
+  [[...]] subvariety
+
+  [[...]] expansion
+
+
+====Superclasses====
+  [[...]] supervariety
+
+  [[...]] subreduct
+
+
+====References====
+
+[(Andreka1991>
+Hajnal Andr\'eka, \emph{Representations of distributive lattice-ordered semigroups with binary relations}, Algebra Universalis \textbf{28} (1991), 12--25
+[[MRreview]]
+)]
+
+