[Home]Modular lattices

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is the smallest nondistributive modular lattice. By a result of Dedekind
is the smallest nondistributive modular lattice. By a result of

Abbreviation: MLat

Definition

A modular lattice is a lattice L = (L,∨,∧) that satisfies the modular identity:   (( xz) ∨y) ∧z = ( xz) ∨( yz) .

Definition

A modular lattice is a lattice L = (L,∨,∧) that satisfies the modular law:   x ≤ z  ⇒  ( xy) ∧z ≤ x∨( yz) .

Definition

A modular lattice is a lattice L = (L,∨,∧) such that L has no sublattice isomorphic to the pentagon N5 = 

Morphisms

Let L and M be modular lattices. A morphism from L to M is a function h : LM that is a homomorphism: h(xy) = h(x)∨h(y)  and  h(xy) = h(x)∧h(y).

Some results

Examples

M3 =  is the smallest nondistributive modular lattice. By a result of [Richard Dedekind, Über die von drei Moduln erzeugte Dualgruppe, Math. Ann. 53 (1900) 371--403] this lattice occurs as a sublattice of every nondistributive modular lattice.

Properties

Classtype variety
Equational theory undecidable [Ralph Freese, Free modular lattices, Trans. Amer. Math. Soc. 261 (1980) 81--91 MRreview]
[Christian Herrmann, On the word problem for the modular lattice with four free generators, Math. Ann. 265 (1983) 513--527 MRreview]
Quasiequational theory undecidable [L. Lipshitz, The undecidability of the word problems for projective geometries and modular lattices, Trans. Amer. Math. Soc. 193 (1974) 171--180 MRreview]
First-order theory undecidable
Locally finite no
Residual size unbounded
Congruence distributive yes
Congruence modular yes
Congruence n-permutable no
Congruence regular no
Congruence uniform no
Congruence extension property no
Definable principal congruences no
Equationally definable principal congruences no
Amalgamation property no
Strong amalgamation property no
Epimorphisms are surjective no

Finite members

[Size 1]?:  1
[Size 2]?:  1
[Size 3]?:  1
[Size 4]?:  2
Size 5:  4
[Size 6]?:  
[Size 7]?:  

Subclasses

Distributive lattices
[Complete modular lattices]?

Superclasses

[Semimodular lattices]?
[Geometric lattices]?


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Last edited June 5, 2003 10:00 am (diff)
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