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17-letter words containing o, n, a, c, l, u

  • nasolacrimal duct — a membranous canal extending from the lacrimal sac to the nasal cavity, through which tears are discharged into the nose.
  • national security — defence of a country
  • natural deduction — (logic)   A set of rules expressing how valid proofs may be constructed in predicate logic. In the traditional notation, a horizontal line separates premises (above) from conclusions (below). Vertical ellipsis (dots) stand for a series of applications of the rules. "T" is the constant "true" and "F" is the constant "false" (sometimes written with a LaTeX \perp). "^" is the AND (conjunction) operator, "v" is the inclusive OR (disjunction) operator and "/" is NOT (negation or complement, normally written with a LaTeX \neg). P, Q, P1, P2, etc. stand for propositions such as "Socrates was a man". P[x] is a proposition possibly containing instances of the variable x, e.g. "x can fly". A proof (a sequence of applications of the rules) may be enclosed in a box. A boxed proof produces conclusions that are only valid given the assumptions made inside the box, however, the proof demonstrates certain relationships which are valid outside the box. For example, the box below labelled "Implication introduction" starts by assuming P, which need not be a true proposition so long as it can be used to derive Q. Truth introduction: - T (Truth is free). Binary AND introduction: ----------- | . | . | | . | . | | Q1 | Q2 | ----------- Q1 ^ Q2 (If we can derive both Q1 and Q2 then Q1^Q2 is true). N-ary AND introduction: ---------------- | . | .. | . | | . | .. | . | | Q1 | .. | Qn | ---------------- Q1^..^Qi^..^Qn Other n-ary rules follow the binary versions similarly. Quantified AND introduction: --------- | x . | | . | | Q[x] | --------- For all x . Q[x] (If we can prove Q for arbitrary x then Q is true for all x). Falsity elimination: F - Q (Falsity opens the floodgates). OR elimination: P1 v P2 ----------- | P1 | P2 | | . | . | | . | . | | Q | Q | ----------- Q (Given P1 v P2, if Q follows from both then Q is true). Exists elimination: Exists x . P[x] ----------- | x P[x] | | . | | . | | Q | ----------- Q (If Q follows from P[x] for arbitrary x and such an x exists then Q is true). OR introduction 1: P1 ------- P1 v P2 (If P1 is true then P1 OR anything is true). OR introduction 2: P2 ------- P1 v P2 (If P2 is true then anything OR P2 is true). Similar symmetries apply to ^ rules. Exists introduction: P[a] ------------- Exists x.P[x] (If P is true for "a" then it is true for all x). AND elimination 1: P1 ^ P2 ------- P1 (If P1 and P2 are true then P1 is true). For all elimination: For all x . P[x] ---------------- P[a] (If P is true for all x then it is true for "a"). For all implication introduction: ----------- | x P[x] | | . | | . | | Q[x] | ----------- For all x . P[x] -> Q[x] (If Q follows from P for arbitrary x then Q follows from P for all x). Implication introduction: ----- | P | | . | | . | | Q | ----- P -> Q (If Q follows from P then P implies Q). NOT introduction: ----- | P | | . | | . | | F | ----- / P (If falsity follows from P then P is false). NOT-NOT: //P --- P (If it is not the case that P is not true then P is true). For all implies exists: P[a] For all x . P[x] -> Q[x] ------------------------------- Q[a] (If P is true for given "a" and P implies Q for all x then Q is true for a). Implication elimination, modus ponens: P P -> Q ---------- Q (If P and P implies Q then Q). NOT elimination, contradiction: P /P ------ F (If P is true and P is not true then false is true).
  • natural harmonics — harmonics of a note produced on a stringed instrument by lightly touching an open or unstopped sounded string.
  • natural resources — a naturally occurring source of wealth, as land or water.
  • natural selection — the process by which forms of life having traits that better enable them to adapt to specific environmental pressures, as predators, changes in climate, or competition for food or mates, will tend to survive and reproduce in greater numbers than others of their kind, thus ensuring the perpetuation of those favorable traits in succeeding generations.
  • natural-resources — a naturally occurring source of wealth, as land or water.
  • neurobiologically — In terms of or by means of neurobiology.
  • neuropathological — (medicine) Of, pertaining to, or arising from neuropathology, the pathology of nerve tissue.
  • neuropharmacology — the branch of pharmacology concerned with the effects of drugs on the nervous system.
  • nicholas bourbaki — the pseudonym of a group of mainly French mathematicians that, since 1939, has been producing a monumental work on advanced mathematics, Eléments de Mathématique
  • nikolaus von cusa — Nicholas (def 1).
  • non-instructional — the act or practice of instructing or teaching; education.
  • nonconstitutional — of or relating to the constitution of a state, organization, etc.
  • nuclear isomerism — isomerism (def 2).
  • nuclear radiation — Physics. radiation in the form of elementary particles emitted by an atomic nucleus, as alpha rays or gamma rays, produced by decay of radioactive substances or by nuclear fission.
  • nuclear threshold — the point in war at which a combatant brings nuclear weapons into use
  • nuclear-free zone — any area in which nuclear weapons, power plants, or materials are not allowed.
  • nuclear-isomerism — Chemistry. the relation of two or more compounds, radicals, or ions that are composed of the same kinds and numbers of atoms but differ from each other in structural arrangement (structural isomerism) as CH 3 OCH 3 and CH 3 CH 2 OH, or in the arrangement of their atoms in space and therefore in one or more properties. Compare optical isomerism, stereoisomerism.
  • numerical control — control of a machine tool, or other device used in a manufacturing process, by a computer, other control circuitry, or recorded digital commands.
  • olympic mountains — a mountain range in NW Washington: part of the Coast Range. Highest peak: Mount Olympus, 2427 m (7965 ft)
  • olympic peninsula — a large peninsula of W Washington
  • opportunistically — adhering to a policy of opportunism; practicing opportunism.
  • optical computing — (hardware)   (Or "Optical Signal Processing") Operating on data represented using electromagnetic radiation, e.g. visible light, instead of the electrical signals used in a conventional electronic digital computer. Electronic digital computers are built from transistors. These form components that store data and logic gates that perform the low-level Boolean operations such as AND, OR and NOT that are the basis of all digital computation. The optical equivalent requires material with a non-linear refractive index such that light beams can interact with each other to perform the same Boolean operations. Though the photons that carry optical signals offer some theoretical advantages over the electrons that carry electronic signals, there are many practical problems that would have to be overcome before optical computing could compete in terms of cost, power and speed.
  • osculating circle — circle of curvature.
  • palace revolution — a challenge to or overthrow of a sovereign or other leader by members of the ruling family or group.
  • papanicolaou test — Pap test.
  • particularization — to make particular.
  • personal computer — a compact computer that uses a microprocessor and is designed for individual use, as by a person in an office or at home or school, for such applications as word processing, data management, financial analysis, or computer games. Abbreviation: PC.
  • phonological rule — an operation in generative phonology that substitutes one sound or class of sounds for another in a phonological derivation.
  • ploughman's lunch — a light lunch consisting of bread and cheese, and sometimes pickled onions.
  • polymorphonuclear — (of a leukocyte) having a lobulate nucleus.
  • pre-qualification — a quality, accomplishment, etc., that fits a person for some function, office, or the like.
  • product placement — Product placement is a form of advertising in which a company has its product placed where it can be clearly seen during a film or television programme.
  • production values — the quality of a media production (such as a film) in regards to elements such as colours, quality, style, etc
  • psychoeducational — designating or of psychological methods, as intelligence tests, used in evaluating learning ability
  • public accountant — an accountant whose services are available to the public at large, in contrast to one employed on a full-time basis by a company.
  • pyroligneous acid — a yellowish, acidic, water-soluble liquid, containing about 10 percent acetic acid, obtained by the destructive distillation of wood: used for smoking meats.
  • quattuordecillion — a cardinal number represented in the U.S. by 1 followed by 45 zeros, and in Great Britain by 1 followed by 84 zeros.
  • radioluminescence — luminescence induced by nuclear radiation.
  • rational function — a function that can be written as the quotient of two polynomials with integral coefficients.
  • recreational drug — drug taken for pleasure
  • recursion formula — a formula for determining the next term of a sequence from one or more of the preceding terms.
  • reduction formula — a formula, such as sin (90° ± A) = cos A, expressing the values of a trigonometric function of any angle greater than 90° in terms of a function of an acute angle
  • reflection nebula — a cloud of interstellar gas and dust that reflects the light of neighboring stars.
  • republic of china — People's Republic of, a country in E Asia. 3,691,502 sq. mi. (9,560,990 sq. km). Capital: Beijing.
  • republic-of-china — People's Republic of, a country in E Asia. 3,691,502 sq. mi. (9,560,990 sq. km). Capital: Beijing.
  • reticulate python — a python, Python reticulatus, of southeastern Asia and the East Indies, sometimes growing to a length of 32 feet (10 meters): usually considered to be the largest snake in the world.
  • return of capital — A return of capital is a situation in which you receive back money that was previously invested.
  • return on capital — A return on capital is any earnings that you receive from the capital that you have invested.
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