A characterization of a special ordering in a root system. (English) Zbl 0799.20037

The author gives necessary and sufficient conditions for an ordering of a set of positive roots in a root system \(R\) to be associated to a reduced expression of an element of the Weyl group of \(R\) and characterizes the sets of positive roots which can be given such an ordering.


20F55 Reflection and Coxeter groups (group-theoretic aspects)
17B20 Simple, semisimple, reductive (super)algebras
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