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2 Lie algebras and breadth
 2.1 Attributes
 2.2 Breadth
 2.3 Inflation of Lie algebras

2 Lie algebras and breadth

2.1 Attributes

2.1-1 LieClass
‣ LieClass( L )( attribute )

Computes the class of the nilpotent Lie algebra L.

2.1-2 LieType
‣ LieType( L )( attribute )

Computes the type of the nilpotent Lie algebra L.

2.1-3 IsOfMaximalClass
‣ IsOfMaximalClass( L )( property )

Returns: true or false

Returns whether the nilpotent Lie algebra L is of maximal class or not.

2.1-4 StructureMatrices
‣ StructureMatrices( L )( attribute )

Computes the structure matrices of the nilpotent Lie algebra L.

2.1-5 BasisLieCenter
‣ BasisLieCenter( L )( attribute )

Returns the elements of the basis Lie algebra L that are contained in the center of L.

2.1-6 BasisLieDerived
‣ BasisLieDerived( L )( attribute )

Returns the elements of the basis Lie algebra L that are contained in the derived subalgebra of L.

2.1-7 LieAdjointMatrix
‣ LieAdjointMatrix( L )( attribute )

Computes the adjoint matrix of the Lie algebra L.

2.1-8 PrintLiePresentation
‣ PrintLiePresentation( L )( attribute )

Prints the Lie presentation of the Lie algebra L.

2.2 Breadth

2.2-1 InfoLieBreadth
‣ InfoLieBreadth( info class )

Info class for the functions of the breadth of Lie algebras.

2.2-2 LieBreadth
‣ LieBreadth( L )( attribute )

Computes the breadth of the Lie algebra L.

2.2-3 IsTrueClassBreadth
‣ IsTrueClassBreadth( L )( property )

Returns: true or false

Returns whether the Lie algebra L holds the class-breadth conjecture or not.

2.2-4 TGroupBreadth
‣ TGroupBreadth( G )( function )

Computes the breadth of the T-groupo G.

2.3 Inflation of Lie algebras

A grading for a Lie algebra L is a decomposition L = \bigoplus_{i=1}^n L_i that respects the Lie bracket, i.e. [L_i,L_j]\subseteq L_{i+j}.}. Any nilpotent Lie algebras can be graded by taking L_i = \gamma_i(L)/\gamma_{i+1}(L). Let L be a nilpotent Lie algebra of maximal class. The two-step centralizers are the sets C_i = C_{L_1}(L_i) = \{x \in L_1 \mid [x,L_i] = 0 \} for all 2\leq i \leq c. Let \mathcal{C}=\{C_i\}\setminus L_1, we say that a Lie algebra of maximal class is covered if the set \mathcal{C} consist of all one-dimensional subspaces of L_1.

Let L be a graded Lie algebra L = \bigoplus_{i=1}^n L_i over K=\F_q for some prime power q=p^n. Consider the field extension A=K[\varepsilon]/\langle \varepsilon^p \rangle which is a vector space over K of dimension p. The algebra A is an associative, commutative and has a unit. The algebra L\otimes A over K defined by [x\otimes a, y\otimes b] = [x,y]\otimes ab is a graded Lie algebra. Let M be a maximal ideal of L and consider the Lie subalgebra M^\uparrow = M\otimes A. Let D be a derivation of L of degree 1. Define D^\uparrow via: D^\uparrow(x\otimes \varepsilon^i)=D(x)\otimes \varepsilon^i, this is a derivation of M^\uparrow of degree 1. Define the derivation E\in \Der M^\uparrow by E(x\otimes \varepsilon^i) = D^\uparrow(x\otimes\varepsilon^i\cdot\varepsilon^{p-1})+1\otimes\partial_\varepsilon(\varepsilon^i). Let s\in L_1\setminus M, take D=\mathrm{ad}_s, and extend it naturally to M^\uparrow. Denote E_{s^\prime} as previously. The inflation {}^{M}L of L at M by s\in L_1\setminus M is the graded Lie algebra obtained as an extension of M^\uparrow by an element s^\prime, which is the extension of s that induces the derivation E_{s^\prime}, that is,

[x\otimes a, s^\prime] = E_{s^\prime}(x\otimes a) = \mathrm{ad}_{s^\prime}(x\otimes\varepsilon^i)+x\otimes\partial_\varepsilon(\varepsilon^i).

2.3-1 InfoInflation
‣ InfoInflation( info class )

Info class for the functions of the inflation of Lie algebras.

2.3-2 LieNilpotentGrading
‣ LieNilpotentGrading( L )( attribute )

Computes a grading of the nilpotent Lie algebra L using the lower central series.

2.3-3 LieTwoStepCentralizers
‣ LieTwoStepCentralizers( L )( attribute )

Computes the two step centralizers of the Lie algebra L.

2.3-4 IsLieCovered
‣ IsLieCovered( L )( property )

Returns: true or false

Returns whether the Lie algebra L is covered or not.

2.3-5 PolynomialAlgebra
‣ PolynomialAlgebra( F )( attribute )

For a finite field F computes the polynomial algebra F[x].

2.3-6 LieCoveredInflated
‣ LieCoveredInflated( n )( attribute )

For n=2,3,4 computes the covered Lie algebras of maximal class using the polynomial algebra of dimension n. For n=3 one can directly load the Lie algebra by reading the file "inflation_3.g".

2.3-7 LieMinimalQuotientClassBreadth
‣ LieMinimalQuotientClassBreadth( L )( attribute )

Given a covered Lie algebras of maximal class L computes the minimal quotient that not holds the class-breadth conjecture.

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