Combinatorial Presentation of Schubert Polynomials
摘要
In the previous chapter we defined Schubert polynomials by means of divided difference operators. Despite the fact that the differences are divided, Schubert polynomials are actual polynomials, not rational functions. More surprisingly, even though these are divided difference operators, the coefficients of Schubert polynomials turn out to be positive, as we saw in Corollary 12.17.