longestWeylGroupElement(RootSystem,Parabolic) -- the longest element of a parabolic subgroup of the Weyl group of a root system

Synopsis

• Function: longestWeylGroupElement

• Usage:

  longestWeylGroupElement(R,P)

• Inputs:
  • R, an instance of the type RootSystem,
  • P, an instance of the type Parabolic,
• Outputs:
  • an instance of the type WeylGroupElement, the longest element of the parabolic sugroup of the Weyl group of R generated by the reflections in P

Description

i1 : R=rootSystemF4;

i2 : longestWeylGroupElement(R,parabolic(R,set{1,2}))

o2 = WeylGroupElement{RootSystem{...8...}, | -1 |}
                                           | -1 |
                                           |  5 |
                                           |  1 |

o2 : WeylGroupElement