[Home]Boolean semilattices

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Difference (from revision 1 to current revision) (minor diff)

Removed: 7d6


Changed: 11,12c10,12
complex algebra of S is Cm(S) = (P(S),∪,Ø,
∩,S,−,·)
, where \langle P(S),\cup,\emptyset,
complex algebra of S is
Cm(S) = (P(S),∪,Ø,∩,S,−,·),
where $\langle P(S),\cup,\emptyset,

Changed: 15c15
X·Y = {x·y | x ∈ Xy ∈ Y}.
X·Y = {x·y | x ∈ Xy ∈ Y}.

Changed: 115c115
[Size 8]?:  ge 96 out of 104

[Size 8]?:   ≥ 97 out of 104


Abbreviation: BSlat

Definition

A Boolean semilattice is a structure A = (A,∨,0, ∧,1,¬,·) such that A is in the variety generated by complex algebras of semilattices.

Let S = (S,·) be a semilattice. The complex algebra of S is Cm(S) = (P(S),∪,Ø,∩,S,−,·), where (P(S),∪,Ø, ∩,S,−) is the Boolean algebra of subsets of S, and

X·Y = {x·y | x ∈ Xy ∈ Y}.

Remark: The complex algebra of any groupoid is a Boolean algebra with one binary operator.

Morphisms

Let A and B be Boolean semilattices. A morphism from A to B is a function h : AB that is a Boolean homomorphism and preserves ·: h(x·y) = h(xh(y).

Some results

Examples

Properties

Classtype variety
[Finitely axiomatizable]? open
Equational theory
Quasiequational theory
First-order theory
Locally finite no
Residual size unbounded
Congruence distributive yes
Congruence modular yes
Congruence n-permutable yes, n = 2
Congruence regular yes
Congruence uniform
Congruence extension property yes
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]?:  0
[Size 4]?:  5
[Size 5]?:  0
[Size 6]?:  0
[Size 7]?:  0
[Size 8]?:   ≥ 97 out of 104

[Some members of BSlat]?

Subclasses

[Variety generated by complex algebras of linear semilattices]?

Superclasses

[Commutative Boolean semigroups]?


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Last edited June 3, 2003 12:12 pm (diff)
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