Article 49 TFEU and Article 11(1)(a) of Council Directive 90/434/EEC on the common system of taxation applicable to mergers, divisions, transfers of assets and exchanges of shares concerning companies of different Member States preclude national legislation, aimed at preventing tax evasion or avoidance, from imposing a condition that the use of the common system of taxation applicable to mergers and transactions treated as such is to be subject to a process of prior approval such as that at issue, which applies only to transfers made to foreign legal persons, but not to transfers made to legal persons incorporated under national law and requires the taxpayer, as a matter of course, to provide proof that an operation is genuine and proper, even where there is no evidence whatsoever of tax evasion or tax avoidance.