a weight is represented by an element of ZZ^n, the basis consisting in the fundamental weights

- Root -- the class of roots (or, more generally, elements of the root lattice)

- - Weight -- the negative of a weight
- eval(RootSystem,Weight,Root) -- evaluate the dual of a root at a Weight
- eval(RootSystem,Weight,ZZ) -- evaluate the dual of a simple root at a Weight
- isPositiveRoot(RootSystem,Weight) -- check whether a weight is a positive root
- isRoot(RootSystem,Weight) -- check whether a weight is a positive root
- reflect(RootSystem,BasicList,Weight) -- apply to a weight several reflections with respect to roots
- reflect(RootSystem,ZZ,Weight) -- apply to a weight the reflection with respect to a root
- rootCoefficients(RootSystem,Weight) -- the coefficients at the simple roots
- scalarProduct(RootSystem,Weight,Weight) -- the scalar product of two weights
- scalarProduct(RootSystem,ZZ,Weight) -- the scalar product of a fundamental weight and a weight
- Weight + Weight -- the sum of two weights
- Weight - Weight -- the difference of two weights
- WeylGroupElement * Weight -- apply an element of a Weyl group to a weight
- ZZ * Weight -- the multiple of a weight

- weight -- construct a weight in the weight lattice of a root system
- weight(RootSystem,BasicList) -- construct a weight from a list
- weight(RootSystem,Vector) -- construct a weight from a vector
- isPositiveRoot -- check whether a weight is a positive root
- isRoot -- check whether a weight is a root or whether a root is in a parabolic sub root system