- Weight -- the negative of a weight

Synopsis

• Operator: -

• Usage:

  - p

• Inputs:
  • p, an instance of the type Weight,
• Outputs:
  • an instance of the type Weight, the negative of p

Description

i1 : R=rootSystemA(4)

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

o1 : RootSystem

i2 : M=cartanMatrix R

o2 = | 2  -1 0  0  |
     | -1 2  -1 0  |
     | 0  -1 2  -1 |
     | 0  0  -1 2  |

              4       4
o2 : Matrix ZZ  <-- ZZ

i3 : p=weight(R,M_2)

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

       4
o3 : ZZ

i4 : -p

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

       4
o4 : ZZ