Table of Contents

Dunn monoid

Abbreviation: DunnMon

Definition

A \emph{Dunn monoid} is a commutative distributive residuated lattice $\mathbf{L}=\langle L, \vee, \wedge, \cdot, e, \to \rangle$ such that

$\cdot$ is square-increasing: $x\le x^2$

Remark: Here $x^2=x\cdot x$. These algebras were first defined by J.M.Dunn in 1) and were named by R.K. Meyer2).

Morphisms

Let $\mathbf{L}$ and $\mathbf{M}$ be Dunn monoids. A morphism from $\mathbf{L}$ to $\mathbf{M}$ is a function $h:L\rightarrow M$ that is a homomorphism:

$h(x\vee y)=h(x)\vee h(y)$, $h(x\wedge y)=h(x)\wedge h(y)$, $h(x\cdot y)=h(x)\cdot h(y)$, $h(x\to y)=h(x)\to h(y)$, and $h(e)=e$

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)= &\\
f(3)= &\\
f(4)= &\\
f(5)= &\\

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

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

\end{array}$

Subclasses

commutative distributive idempotent residuated lattices subvariety

bounded Dunn monoids expansion

Superclasses

commutative distributive residuated lattices supervariety

square-increasing commutative residuated lattices supervariety

References


1) J.M. Dunn: The Algebra of Intensional Logics, PhD thesis, University of Pittsburgh, 1966.
2) R.K. Meyer: Conservative extension in relevant implication, Studia Logica 31 (1972), 39–46.
3) A. Urquhart: The undecidability of entailment and relevant implication, J. Symbolic Logic 49 (1984), 1059–1073.