State immunity — Jurisdictional immunity — Taxation — Educational Institute of Federal Republic of Germany in Spain — Liability to payment of municipal rates — Claim to exemption by Federal Republic of Germany — Cultural Agreement between Federal Republic of Germany and Spain, 1966 — Whether automatic entitlement to exemption from municipal taxation

Treaties — Effect in municipal law — Entry into force — Requirements — Ratification — Publication in State official journal — Principle of non-retroactivity — Priority of treaty provisions over conflicting provisions of municipal law — Conditions for direct applicability of treaty provisions — Spanish Constitution, Article 96 — New Civil Code, Article 1(5)

Relationship of international law and municipal law — Treaties — Effect in municipal law — Conditions for incorporation of treaty provisions into municipal law — The law of Spain