tax law
(21) The term tax law of a country includes statutes, regulations, administrative or judicial rulings, and income tax treaties of the country. If a country has an income tax treaty with the United States that applies to taxes imposed by a political subdivision or other local authority of that country, then the tax law of the political subdivision or other local authority is deemed to be a tax law of a country. When used with respect to a tax resident or branch, tax law refers to -