−Table of Contents
Generalized Boolean algebras
Abbreviation: GBA
Definition
A \emph{generalized Boolean algebra} is a Brouwerian algebras A=⟨A,∨,∧,1,→⟩ such that
x∨y=(x→y)→y
Morphisms
Let A and B be generalized Boolean algebras. A morphism from A to B is a function h:A→B that is a homomorphism:
h(x∨y)=h(x)∨h(y), h(x∧y)=h(x)∧h(y) andh(1)=1, h(x→y)=h(x)→h(y)
Examples
Example 1:
Basic results
Properties
Classtype | variety |
---|---|
Equational theory | decidable |
Quasiequational theory | decidable |
First-order theory | decidable |
Locally finite | yes |
Residual size | 2 |
Congruence distributive | yes |
Congruence modular | yes |
Congruence n-permutable | yes, n=2 |
Congruence regular | yes |
Congruence e-regular | yes, e=1 |
Congruence uniform | yes |
Congruence extension property | yes |
Definable principal congruences | yes |
Equationally def. pr. cong. | yes |
Amalgamation property | yes |
Strong amalgamation property | yes |
Epimorphisms are surjective | yes |
Finite members
f(1)=1f(2)=1f(3)=0f(4)=1f(5)=0f(6)=0