** international: country code-56 ; submarine cables provide links to the US and to Central and South America ; satellite earth stations-2 Intelsat ( Atlantic Ocean ) ( 2007 )

** international: satellite earth stations-2 Intelsat ( 1 Indian Ocean and 1 Pacific Ocean )

** Satellite earth station: Intersputnik ( Indian Ocean Region ) Intelsat, Asiasat-1

** international: country code-82 ; 10 fiber-optic submarine cables-1 Korea-Russia-Japan, 1 Korea-Japan-Hong Kong, 3 Korea-Japan-China, 1 Korea-Japan-China-Europe, 1 Korea-Japan-China-US-Taiwan, 1 Korea-Japan-China, 1 Korea-Japan-Hong Kong-Taiwan, 1 Korea-Japan ; satellite earth stations-3 Intelsat ( 1 Pacific Ocean and 2 Indian Ocean ) and 3 Inmarsat ( 1 Pacific Ocean and 2 Indian Ocean )

** Intelsat IV ( F2 ) is launched ; it enters commercial service over the Atlantic Ocean March 26.

** International Telecommunications Satellite Organization ( Intelsat ) ( effective 12 February 1973 ).

** international: country code-975 ; international telephone and telegraph service via landline and microwave relay through India ; satellite earth station-1 Intelsat ( 2007 )

** Andronikos IV Palaiologos ( 1348 – 1385 )

** Philip IV ( 1285 – 1314 )

** Charles IV ( 1322 – 1328 )

** Henry IV ( 1589 – 1610 )

** Alphonse IV ( 1325 – 1357 )

** Ferdinand IV ( 1759 – 1806 )

** Louis IV ( 1715 – 1774 )

** Charles IV ( 1788 – 1808, 1808 )

** Hugh IV ( 1218 – 1272 )

** Odo IV ( 1315 – 1349 )

** John IV ( 1341 – 1345 )

** Francis IV ( 1524 – 1532 )

** John IV ( 1415 – 1427 )

** João IV ( 1640 – 1656 )

** Pedro IV ( 1826 )

** On the Terrors of Death ( Epistle IV )

** " Part IV: GPS heighting " SaLIS Vol.

** Philip IV the Fair, 1285 – 1314

** Charles IV the Fair, 1322 – 1328

** Henry IV the Great, 1589 – 1610

** Uruk IV period: 3300 – 3000 BC

** In the Star Trek: Voyager episode " One Small Step ", USS Voyager discovers the fate of Ares IV, one of the first manned expeditions to Mars in 2032.

** DNA Polymerase IV ( DinB ) – SOS repair polymerase

** IV.

** Conrad ( 1087 – 1098, nominal king under his father Henry IV )

** An F3 tornado away from the Westminster, Maryland city center injures 3 people and causes $ 5 million in damages.

** Tornado F3 Wing-14 Tornado F3s at Prince Sultan in Saudi Arabia

** F3 Thin Films and Surfaces

** Eunectes murinus, the green anaconda, the largest species, is found east of the Andes in Colombia, Venezuela, the Guianas, Ecuador, Peru, Bolivia, Brazil and on the island of Trinidad.

** Eunectes notaeus, the yellow anaconda, a smaller species, is found in eastern Bolivia, southern Brazil, Paraguay and northeastern Argentina.

** Eunectes deschauenseei, the dark-spotted anaconda, is a rare species found in northeastern Brazil and coastal French Guiana.

** Eunectes beniensis, the Bolivian anaconda, the most recently defined species, is found in the Departments of Beni and Pando in Bolivia.

** Tarski's theorem: For every infinite set A, there is a bijective map between the sets A and A × A.

** The Cartesian product of any family of nonempty sets is nonempty.

** König's theorem: Colloquially, the sum of a sequence of cardinals is strictly less than the product of a sequence of larger cardinals.

** Hausdorff maximal principle: In any partially ordered set, every totally ordered subset is contained in a maximal totally ordered subset.

** For every non-empty set S there is a binary operation defined on S that makes it a group.

** Tychonoff's theorem stating that every product of compact topological spaces is compact.

** In the product topology, the closure of a product of subsets is equal to the product of the closures.

** If S is a set of sentences of first-order logic and B is a consistent subset of S, then B is included in a set that is maximal among consistent subsets of S. The special case where S is the set of all first-order sentences in a given signature is weaker, equivalent to the Boolean prime ideal theorem ; see the section " Weaker forms " below.

** Any union of countably many countable sets is itself countable.

** If the set A is infinite, then there exists an injection from the natural numbers N to A ( see Dedekind infinite ).

** Every infinite game in which is a Borel subset of Baire space is determined.

** The Vitali theorem on the existence of non-measurable sets which states that there is a subset of the real numbers that is not Lebesgue measurable.

** The Lebesgue measure of a countable disjoint union of measurable sets is equal to the sum of the measures of the individual sets.

** The Nielsen – Schreier theorem, that every subgroup of a free group is free.