Given a Lie algebra L, return whether L is solvable.
Given a Lie algebra L, return whether L is nilpotent.
Let L be a Lie algebra over a field of characteristic p>0. Then L is called restricted if the Lie algebra ( ad) L is closed under the p-th power map (which associates to a matrix its p-th power). This function returns whether L is restricted. Lie algebras of characteristic zero are never restricted. Furthermore, it is enough to test the property for a basis of L.
Given a Lie algebra L, this function returns whether L has a Levi subalgebra. If the result is true, then the function also returns a semisimple subalgebra (complement to the solvable radical) of L. If L is defined over a field of characteristic 0, then it always has a Levi subalgebra. However, if L is a Lie algabra of characteristic p>0 then L need not have a Levi subalgebra but the function will always find one if one exists.
> L:=SimpleLieAlgebra("D",3,RationalField()); > L; Lie Algebra of dimension 15 with base ring Rational Field > K:=sub< L | [L.1,L.2,L.3] >; > M:=Centralizer( L, K ); > M; Lie Algebra of dimension 4 with base ring Rational Field > R:=SolvableRadical(M); > R; Lie Algebra of dimension 4 with base ring Rational Field > HasLeviSubalgebra(M); true Lie Algebra of dimension 0 with base ring Rational Field > K:=Centralizer(L, sub< L | [L.1,L.2,L.3] >); > K; Lie Algebra of dimension 4 with base ring Rational Field > IsSolvable(K); true > IsNilpotent(K); true > R:= SolvableRadical(K); > IsSolvable(R); true > IsNilpotent(R); true > N:= NilRadical(K); > IsNilpotent(N); trueWe now construct a Lie algebra which is restricted.
> M:=SimpleLieAlgebra("B",3,GF(5)); > M; Lie Algebra of dimension 21 with base ring GF(5) > IsRestrictedLieAlgebra( M ); true