Additional files for the article
Codimension in planar polynomial differential systems

Joan C. Artés, J. Llibre, D. Schlomiuk and N. Vulpe

In this paper we get deeply into the concept of codimension applied to planar polynomial differential systems. We extend the concept of codimension to different elements related with polynomial differential systems, i.e. singularities, configurations of singularities, phase portraits, and not only from the topological point of view but also from a geometrical one. We will discover tricky situations which will force us to adapt the definitions. The codimension will be an important tool in a global classification of phase portraits, starting for the quadratic differential systems. We also propose a nomenclature to give a definitive code to every quadratic phase portrait.