Table of Contents

Skew lattices

Abbreviation: SkLat

Definition

A \emph{skew lattice} is a structure $\mathbf{A}=\langle A,\vee,\wedge\rangle,$ of type $\langle 2,2\rangle$ such that

$\langle A,\vee\rangle$ is a band,

$\langle A,\wedge\rangle$ is a band,

and the following absorption laws hold: $x\wedge (x\vee y)=x=x\vee (x\wedge y)$, $(x\vee y)\wedge y=y=(x\wedge y)\vee y$.

Morphisms

Let $\mathbf{A}$ and $\mathbf{B}$ be skew lattices. A morphism from $\mathbf{A}$ to $\mathbf{B}$ is a function $h:A\rightarrow B$ that is a homomorphism: $h(x \vee y)=h(x) \vee h(y)$, $h(x \wedge y)=h(x) \wedge h(y)$,

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.

Finite members

$\begin{array}{lr}

f(1)= &1\\
f(2)= &3\\
f(3)= &7\\
f(4)= &\\
f(5)= &\\

\end{array}$ $\begin{array}{lr}

f(6)= &\\
f(7)= &\\
f(8)= &\\
f(9)= &\\
f(10)= &\\

\end{array}$

Subclasses

[[Lattices]] expanded type
[[Rectangular_bands]] expanded type

Superclasses

[[Semigroups]] reduced type

References

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1) Leech, J., Skew lattices in rings, Alg. Universalis 26 (1989), 48–72. [(Leech1993> Leech, J., The geometric structure of skew lattices, Trans. Amer. Math. Soc. 35 (1993), 823–842. [(Leech1996> Leech, J., Recent developments in the theory of skew lattices, Semigroup Forum 52 (1996), 7–24.