Judgment of the Court of Justice in the case X.
1. Article 49 TFEU must be interpreted as precluding a Member State, the tax legislation of which permits the deduction of ‘negative income' relating to a dwelling, from refusing the benefit of that deduction to a self-employed non-resident where that person receives, within that Member State, 60% of his total income and does not receive, within the Member State where his dwelling is located, income that enables him to qualify for an equivalent right to deduct.
2. The injunction imposed by the answer to the first question concerns any Member State of activity within which a self-employed person receives income enabling him to claim there an equivalent right of deduction, in proportion to the share of that income received within each Member State of activity. In that regard, a ‘Member State of activity' is any Member State that has the power to tax such income from the activities of a non-resident as is received within its territory, irrespective of where the activities are actually performed.
3. The fact that the non-resident taxpayer concerned receives part of his taxable income not within a Member State, but within a non-Member State, is of no relevance to the answer to the second question.