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17-letter words containing d, e, l, i, r, u

  • naked singularity — an infinitely dense point mass without a surrounding black hole
  • 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).
  • 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.
  • old wives' summer — a period of fine, summerlike weather occurring in Europe in autumn.
  • period-revolution — a rather large interval of time that is meaningful in the life of a person, in history, etc., because of its particular characteristics: a period of illness; a period of great profitability for a company; a period of social unrest in Germany.
  • police procedural — a mystery novel, film, or television drama that deals realistically with police work.
  • postural drainage — a therapy for clearing congested lungs by placing the patient in a position for drainage by gravity, often accompanied by percussion with hollowed hands.
  • prelingually deaf — deaf from birth or having acquired deafness before learning to speak
  • pressure altitude — the altitude for a given pressure in a standard atmosphere, such as that registered by a pressure altimeter.
  • production values — the quality of a media production (such as a film) in regards to elements such as colours, quality, style, etc
  • pseudepigraphical — certain writings (other than the canonical books and the Apocrypha) professing to be Biblical in character.
  • pseudo-historical — of, pertaining to, treating, or characteristic of history or past events: historical records; historical research.
  • pseudo-moralistic — a person who teaches or inculcates morality.
  • pull your head in — be quiet!
  • purely and simply — You use purely and simply to emphasize that the thing you are mentioning is the only thing involved.
  • purple granadilla — the edible fruit of any of several species of passionflower, especially Passiflora edulis (purple granadilla) or P. quadrangularis (giant granadilla)
  • 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.
  • recreational drug — drug taken for pleasure
  • recurring decimal — Mathematics. repeating decimal.
  • red-billed quelea — any of several African weaverbirds of the genus Quelea, especially Q. quelea (red-billed quelea) noted for its vast flocks that destroy grain crops.
  • reduce to silence — If someone or something reduces you to silence, they make you feel so upset or confused that you cannot speak.
  • 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
  • relative humidity — the amount of water vapor in the air, expressed as a percentage of the maximum amount that the air could hold at the given temperature; the ratio of the actual water vapor pressure to the saturation vapor pressure. Abbreviation: RH, rh.
  • reproductive cell — gamete.
  • ring-tailed lemur — a Madagascan prosimian primate, Lemur catta, with a long black and white ringed tail
  • rio grande do sul — a state in S Brazil. 107,923 sq. mi. (279,520 sq. km). Capital: Pôrto Alegre.
  • road-fund licence — a licence showing that the tax payable in respect of a motor vehicle has been paid
  • secondary quality — one of the qualities attributed by the mind to an object perceived, such as color, temperature, or taste.
  • securities dealer — a person who buys and sells securities
  • self-introduction — the act of introducing or the state of being introduced.
  • self-reproduction — the act or process of reproducing.
  • sexual dimorphism — the condition in which the males and females in a species are morphologically different, as with many birds.
  • sheltered housing — accommodation designed esp for the elderly or infirm consisting of a group of individual premises, often with some shared facilities and a caretaker
  • simulated leather — fake leather that is an imitation of real leather and is usually made from a cheaper material
  • south farmingdale — a town on central Long Island, in SE New York.
  • spruce gall aphid — any of various homopterous insects of the family Adelgidae, as Adelges abietis (spruce gall aphid) and Pineus pinifoliae (pine leaf aphid) that feed and form galls on conifers.
  • stannous chloride — a white, crystalline, water-soluble solid, SnCl 2 ⋅2H 2 O, used chiefly as a reducing and tinning agent, and as a mordant in dyeing with cochineal.
  • stannous fluoride — a white, crystalline powder, SnF 2 , slightly soluble in water: used as a source of fluorine in the prevention of dental caries, especially as a toothpaste additive.
  • strange interlude — a play (1928) by Eugene O'Neill.
  • subsidiary ledger — (in accounting) a ledger containing a group of detailed and related accounts the total of which is summarized in the control account.
  • sulfonyl chloride — a colorless liquid, SO 2 Cl 2 , having a very pungent odor and corrosive to the skin and mucous membranes: used as a chlorinating or sulfonating agent.
  • surgical dressing — a dressing made of cotton, used for incisions made during surgery
  • surrender to bail — to present oneself at court at the appointed time after having been on bail
  • sustained-release — (of a drug or fertilizer) capable of gradual release of an active agent over a period of time, allowing for a sustained effect; timed-release; long-acting; prolonged-action; slow-release.
  • temporomandibular — of, relating to, or situated near the hinge joint formed by the lower jaw and the temporal bone of the skull.
  • the evil day/hour — If someone is putting off the evil day or the evil hour, they have to do something unpleasant and are trying to avoid doing it for as long as possible.
  • the outside world — You can use the outside world to refer to all the people who do not live in a particular place or who are not involved in a particular situation.
  • thermal diffusion — the separation of constituents, often isotopes, of a fluid under the influence of a temperature gradient.
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