2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/59594This is the writeup of a talk given at the European Congress of Mathematics, Barcelona. It considers Picard-Lefschetz theory from the Floer cohomology viewpoint.20 pages, LaTeX2e. TeXnical problem should now be fixed, so that the images will appear even if you download the .ps fileSymplectic GeometryAlgebraic Geometrytext