[Home]Basic logic algebras

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Abbreviation: BLA

Definition

A basic logic algebra or BL-algebra is a structure A = (A,∨,0,∧,1,·,→) such that
(A,∨,0,∧,1) is a bounded lattice,
(A,·,1) is a commutative monoid,
gives the residual of ·:   x·y ≤ z  ⇔   y ≤ xz,
linearity:   ( xy) ∨( yx)  = 1, and
BL:   x·(xy) = xy.

Remark: The BL identity implies that the lattice is distributive.

Definition

A basic logic algebra is a FLe-algebra A = (A,∨,0,∧,1,·,→) such that
linearity:   ( xy) ∨( yx)  = 1, and
BL:   x·(xy) = xy.

Remark: The BL identity implies that the identity element 1 is the top of the lattice.

Morphisms

Let A and B be basic logic algebras. A morphism from A to B is a function h : AB that is a homomorphism: h(xy) = h(x)∨h(y)  and  h(1) = 1  and  h(xy) = h(x)∧h(y)  and  h(0) = 0  and  h(x·y) = h(xh(y)  and  h(xy) = h(x)→h(y) hold.

Some results

Examples

Properties

Classtypevariety
Equational theorydecidable
Quasiequational theory
First-order theory
Locally finiteno
Residual sizeunbounded
Congruence distributiveyes
Congruence modularyes
Congruence n-permutableyes, n = 2
Congruence e-regularyes, e = 1
Congruence uniformno
Congruence extension propertyyes
Definable principal congruences
Equationally definable principal congruencesno
Amalgamation property
Strong amalgamation property
Epimorphisms are surjective

Finite members

[Size 1]?:  1
[Size 2]?:  1
[Size 3]?:  1

Subclasses

MV-algebras
Heyting algebras

Superclasses

[Generalized basic logic algebras]?
FLew-algebras?


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Last edited August 6, 2003 4:27 pm (diff)
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