76.19 PermMatY

PermMatX( W, M )

Let M be a linear transformation of the vector space Vdual on which the Coxeter datum W acts which preserves the set of coroots. PermMatY returns the corresponding permutation of the coroots; it signals an error if M does not normalize the set of coroots.

We continue the example from MatYPerm and obtain:

    gap> PermMatY( W, my ) = w0;
    true 

This function requires the package "chevie" (see RequirePackage).

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