Macaulay2 » Documentation
Packages » WeylGroups > RootSystem > rootSystem(RootSystem,Parabolic)
next | previous | forward | backward | up | index | toc

rootSystem(RootSystem,Parabolic) -- the root system of the Levy subgroup of a parabolic

Synopsis

Description

i1 : R1=rootSystemD(4)

o1 = RootSystem{...8...}

o1 : RootSystem
i2 : P=parabolic(R1,set{1,3,4})

o2 = set {4, 1, 3}

o2 : Parabolic
i3 : R2=rootSystem(R1,P)

o3 = RootSystem{...8...}

o3 : RootSystem
i4 : dynkinType(R2)

o4 = DynkinType{{A, 1}, {A, 1}, {A, 1}}

o4 : DynkinType

Ways to use this method: