[Home]Action algebras

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Abbreviation: Act

Definition

An action algebra is a structure A = (A,∨,0,·,1,*,\,/) of type (2,0,2,0,1,2,2) such that
(A,∨,0,·,1,*) is a Kleene algebra,
\ is the left residual of ·:   y ≤ x\z  ⇔   xy ≤ z, and
/ is the right residual of ·:   x ≤ z/y  ⇔   xy ≤ z.

Remark:

Morphisms

Let A and B be action algebras. A morphism from A to B is a function h : AB that is a homomorphism: h(xy) = h(x)∨h(y)  and  h(x·y) = h(xh(y)  and  h(x\y) = h(x)\h(y)  and  h(x/y) = h(x)/h(y)  and  h(x*) = h(x)*  and  h(0) = 0  and  h(1) = 1.

Some results

Examples

Properties

Classtype variety
Equational theory
Quasiequational theory undecidable
First-order theory undecidable
Locally finite no
Residual size unbounded
Congruence distributive
Congruence modular
Congruence n-permutable
Congruence regular
Congruence uniform
Congruence extension property
Definable principal congruences
Equationally definable principal congruences
Amalgamation property
Strong amalgamation property
Epimorphisms are surjective

Finite members

[Size 1]?:  1
[Size 2]?:  1
[Size 3]?:  3
[Size 4]?:  16
[Size 5]?:  149
[Size 6]?:  1488

Subclasses

Action lattices

Superclasses

Kleene algebras
[Residuated join-semilattices]?


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Last edited November 7, 2004 4:16 pm (diff)
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