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WeylGroups :: isRoot(RootSystem,Parabolic,Root)

isRoot(RootSystem,Parabolic,Root) -- check whether a root is in the sub root system of the parabolic

Synopsis

Description

i1 : R=rootSystemE(6)

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

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

o2 = set {1, 3}

o2 : Parabolic
i3 : r1=simpleRoot(R,1)

o3 = |  2 |
     |  0 |
     | -1 |
     |  0 |
     |  0 |
     |  0 |

o3 : Root
i4 : r2=simpleRoot(R,2)

o4 = |  0 |
     |  2 |
     |  0 |
     | -1 |
     |  0 |
     |  0 |

o4 : Root
i5 : isRoot(R,P,r1)

o5 = true
i6 : isRoot(R,P,r2)

o6 = false