Demazure modules, opposite and their intersection are in natural correspondence respectively with Schubert varieties, opposite and  Richardson varieties. The classical Borel-Weil theorem explains this correspondence. It provides a geometric definition of irreducible highest weight...

The chain polynomial of a finite lattice \( \mathcal{L} \) is given by \( p_\mathcal{L} (x) = \sum_{k \geq 0} c_k(\mathcal{L})x^k \), where \( c_k(\mathcal{L}) \) is the number of chains of length \( k \) in \( \mathcal{L} \). The chain polynomials of posets in several important classes have...

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