Given a Lagrangian submanifold in a symplectic manifold and a Morse function
on the submanifold, we show that there is an isotopic Morse function and a
symplectic Lefschetz pencil on the manifold extending the Morse function to the
whole manifold. From this construction we define a sequence of symplectic
invariants classifying the isotopy classes of Lagrangian spheres in a
symplectic 4-manifold.Comment: 40 pages, 1 figur
