Abstract : In a classical Symbolic Perturbation scheme,
degeneracies are handled by substituting some polynomials in
$\varepsilon$ to the input of a predicate. Instead of a single
perturbation, we propose to use a sequence of (simpler)
perturbations. Moreover, we look at their effects geometrically
instead of algebraically; this allows us to tackle cases that were
not tractable with the classical algebraic approach.