Case T-405/11: Judgment of the General Court of 15 November 2018 — Axa Mediterranean v Commission (State aid — Provisions concerning corporate tax allowing undertakings which are tax resident in Spain to amortise the goodwill resulting from the acquisition of shareholdings in undertakings which are tax resident abroad — Decision declaring the aid to be incompatible with the internal market and ordering its recovery — Concept of State aid — Selectivity — Reference system — Derogation — Difference in treatment — Justification of the difference in treatment — Undertakings benefiting from the measure — Legitimate expectations)