17-letter words containing c, o, r, n, u, t
- multiple cropping — the use of the same field for two or more crops, whether of the same or of different kinds, successively during a single year.
- munitions factory — a factory where munitions are made
- 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.
- neuropathological — (medicine) Of, pertaining to, or arising from neuropathology, the pathology of nerve tissue.
- neuropsychiatrist — A medical doctor specializing in neuropsychiatry; a medical doctor dealing with disorders that have both neurological and psychiatric features.
- neuropsychologist — A neurologist or psychologist whose speciality is neuropsychology.
- non-instructional — the act or practice of instructing or teaching; education.
- nonproductiveness — The quality of being nonproductive.
- northcountrywoman — a female native or inhabitant of the North of England
- norwegian current — an ocean current formed from the terminus of the North Atlantic Current, flowing N along the Norwegian coast into the Barents Sea.
- notebook computer — laptop, portable
- 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
- 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.
- nursery education — education provided at a school for young children, usually from three to five years old
- odour of sanctity — sanctimoniousness
- on cruise control — If you say that someone is on cruise control in a contest, you mean that they are winning the contest easily and without needing to make a lot of effort.
- opportunistically — adhering to a policy of opportunism; practicing opportunism.
- organ-pipe cactus — a treelike or columnar cactus, Lemaireocereus marginatus, of Mexico, having a central, erect spine surrounded by spreading spines in clusters of five to eight, and funnel-shaped, brownish-purple flowers.
- osculating circle — circle of curvature.
- out for the count — If someone is out for the count, they are unconscious or very deeply asleep.
- overconscientious — Excessively conscientious.
- overnight success — sth or sb suddenly popular
- palace revolution — a challenge to or overthrow of a sovereign or other leader by members of the ruling family or group.
- particularization — to make particular.
- per procurationem — by one acting as an agent; by proxy.
- percussion bullet — a bullet that is exploded by percussion
- periodic function — a function of a real or complex variable that is periodic.
- permanent account — A permanent account is an account which carries its balance and is kept open from year to year.
- 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.
- pinpoint accuracy — extreme accuracy
- point of purchase — designating or in use at a retail outlet where an item can be purchased; point-of-sale: point-of-purchase displays to entice the buyer.
- point-of-purchase — designating or in use at a retail outlet where an item can be purchased; point-of-sale: point-of-purchase displays to entice the buyer.
- post-resurrection — the act of rising from the dead.
- pre-communication — the act or process of communicating; fact of being communicated.
- pre-configuration — the relative disposition or arrangement of the parts or elements of a thing.
- pre-qualification — a quality, accomplishment, etc., that fits a person for some function, office, or the like.
- prescription drug — medication available only on doctor's instruction
- primary education — junior, elementary schooling
- private education — education provided by a private individual or organization, rather than by the state or a public body
- 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 number — a specialty number or routine, usually performed by the entire cast consisting of musicians, singers, dancers, stars, etc., of a musical comedy, vaudeville show, or the like.
- production string — A production string is the series of pipes through which the oil or gas is brought up from the reservoir.
- production system — (programming) A production system consists of a collection of productions (rules), a working memory of facts and an algorithm, known as forward chaining, for producing new facts from old. A rule becomes eligible to "fire" when its conditions match some set of elements currently in working memory. A conflict resolution strategy determines which of several eligible rules (the conflict set) fires next. A condition is a list of symbols which represent constants, which must be matched exactly; variables which bind to the thing they match and "<> symbol" which matches a field not equal to symbol. Example production systems are OPS5, CLIPS, flex.