$\mathcal F $ in the complex projective plane then one has $\partial^{\underline {\circ}}
C\leq\partial^{\underline {\circ}}\mathcal F+ 2+ a $ where $ a $ is an integer obtained from a
concrete problem of imposing singularities to projective plane curves. If $\mathcal F $ is
nondicritical or if $ C $ has only nodes as singularities, then one gets $ a= 0$ and we
recover known bounds. We also prove proximity formulae for foliations and we use these …