“…Such a progress would not have been possible without the contribution of a long list of articles around the Lefschetz slicing principle, from which we took a part of the inspiration, such as [AF,Ch1,Ch2,Fu,FL,GM,HL1,HL2,HL3,La,Lef,Li,Lo,Mi]. Results of Zariski-van Kampen type have been proved by Libgober for generic Lefschetz pencils of hyperplanes and in the particular case when X is the complement in P n or C n of a hypersurface with isolated singularities [Li].…”