Table of Contents
Lattice-ordered rings
Abbreviation: LRng
Definition
A \emph{lattice-ordered ring} (or $\ell$\emph{-ring}) is a structure $\mathbf{L}=\langle L,\vee,\wedge,+,-,0,\cdot\rangle$ such that
$\langle L,\vee,\wedge\rangle$ is a lattice
$\langle L,+,-,0,\cdot\rangle $ is a ring
$+$ is order-preserving: $x\leq y\Longrightarrow x+z\leq y+z$
${\uparrow}0$ is closed under $\cdot$: $0\leq x,y\Longrightarrow 0\leq x\cdot y$
Remark:
Definition
Morphisms
Let $\mathbf{L}$ and $\mathbf{M}$ be $\ell $-rings. A morphism from $\mathbf{L}$ to $\mathbf{M}$ is a function $f:L\rightarrow M$ that is a homomorphism: $f(x\vee y)=f(x)\vee f(y)$, $f(x\wedge y)=f(x)\wedge f(y)$, $f(x\cdot y)=f(x)\cdot f(y)$, $f(x+y)=f(x)+f(y)$.
Examples
Basic results
The lattice reducts of lattice-ordered rings are distributive lattices.
Properties
| Classtype | variety |
|---|---|
| Equational theory | |
| Quasiequational theory | |
| First-order theory | |
| Congruence distributive | yes, see lattices |
| Congruence extension property | |
| Congruence n-permutable | yes, $n=2$, see groups |
| Congruence regular | yes, see groups |
| Congruence uniform | yes, see groups |
Finite members
$\begin{array}{lr} None \end{array}$