2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/164864We show that for an algebraic reductive group $G$, the partition of a double Schubert cell in the flag variety $G/B$ defined by Deodhar, and coming from a Bialynicki-Birula decomposition, is not a stratification in general. We give a counterexample for a group of type B$_n$, where the closure of some specific cell of dimension $2n$ has a non-trivial intersection with a cell of dimension $3n-3$8 pagesAlgebraic GeometryGroup Theorytext