** Pope Celestine I ( Roman Catholic Church )

** Pope Sixtus I

** Pope Stephen I

** Stephen I of Hungary

** Aristotelian commentaries: Metaphysics, Prior Analytics I, Topics, De sensu and Meteorology,

** Andronikos I Komnenos ( 1118 – 1185 )

** Andronikos I of Trebizond ( 1222 – 1235 )

** " Hello, John ," I said.

** Bayezid I Mosque and complex ( külliye )

** To form the passive voice: " I was told that you wanted to see me "

** Cassius Dio's account of Claudius ' reign, part I

** Henry I ( 1031 – 1060 )

** Philip I ( 1060 – 1108 )

** John I ( 1316 )

** Francis I ( 1515 – 1547 )

** Alphonse I ( 1139 – 1185 )

** Sancho I ( 1185 – 1211 )

** Peter I ( 1357 – 1367 )

** Ferdinand I ( 1367 – 1383 )

** Charles I ( 1266 – 1285 )

** Joanna I ( 1343 – 1382 )

** René I ( 1435 – 1442 )

** Charles I ( 1266 – 1285 )

** Ferdinand I ( 1815 – 1825 )

** Francis I ( 1825 – 1830 )

** 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.

** Well-ordering theorem: Every set can be well-ordered.

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

** Trichotomy: If two sets are given, then either they have the same cardinality, or one has a smaller cardinality than the other.

** 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.

** Every surjective function has a right inverse.

** Zorn's lemma: Every non-empty partially ordered set in which every chain ( i. e. totally ordered subset ) has an upper bound contains at least one maximal element.

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

** Tukey's lemma: Every non-empty collection of finite character has a maximal element with respect to inclusion.

** Antichain principle: Every partially ordered set has a maximal antichain.

** Every vector space has a basis.

** Every unital ring other than the trivial ring contains a maximal ideal.

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

** The closed unit ball of the dual of a normed vector space over the reals has an extreme point.

** 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.