2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/63422We give a lower bound for the value at q=1 of a Kazhdan-Lustig polynomial in a Weyl group W in terms of "patterns''. This is expressed by a "pattern map" from W to W' for any parabloic subgroup W'. This notion generalizes the concept of patterns and pattern avoidance for permutations to all Weyl groups. The main tool of the proof is a "hyperbolic localization" on intersection cohomology; see the related paper http://front.math.ucdavis.edu/math.AG/020225114 pages; updated references. Final version; will appear in Transformation Groups vol.8, no. 4Representation TheoryAlgebraic GeometryCombinatorics14M15, 20F55text