** The Ballad of the White Horse by G. K. Chesterton ( 1911 )

** K ' iche ' ( Quiché )

** K. pedicularius

** K. pusillus

** K. dalmatinus

** K. rufilabris

** In genomics, as a measure of evolution at the protein level ( also denoted as d < sub > N </ sub >/ d < sub > S </ sub > or K < sub > a </ sub >/ K < sub > s </ sub > ratio ).

** ketamine ( K ; Ketalar, Ketaset, Ketanest ; " Ket ", " Kit Kat ", " Special-K ", " Vitamin K ", " Jet Fuel ", " Horse Tranquilizer ")

** SSC Biomedical Physiology and Kinesiology ( K )

** 1 × AGM-84H / K SLAM-ER missile

** U. K. ( album ), the debut, self-titled album from the band UK

** 25 Years of presidency of U. K. Kekkonen.

** President U. K. Kekkonen 75th Birthday.

** K. G. von Wächter, Beiträge zur deutschen Geschichte, insbesondere des deutschen Strafrechts ( Tübingen, 1845 )

** Talks between the government and strikers begin in the U. K.

** Dutch submarine HNLMS K XVI is the first Allied ship to sink a Japanese warship, sinking the destroyer Sagiri near Sarawak ; K XVI is herself torpedoed the following day by Japanese submarine I 66.

** K. Barry Sharpless, American chemist, Nobel Prize laureate

** The Dartford Tunnel opens in the U. K.

** The Beatles ' second U. K. album, With The Beatles, is released

** A. K.

** U. K. Home Secretary Merlyn Rees ends Special Category Status for those sentenced for scheduled terrorist crimes relating to the civil violence in Northern Ireland.

** The A. E. K.

** 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.