reduction

reduction, in chemistry: see oxidation and reduction.

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reduction

Any of a class of chemical reactions in which the number of electrons associated with an atom or group of atoms is increased. The electrons taken up by the substance reduced are supplied by another substance, often hydrogen (H₂), which is thereby oxidized. See also oxidation-reduction.

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reduction

Maths

a. the process of converting a fraction into its decimal form

b. the process of dividing out the common factors in the numerator and denominator of a fraction; cancellation

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reduction [ri′dək·shən]

(analytical chemistry)

Preparation of one or more subsamples from a sample of material that is to be analyzed chemically.

(chemistry)

Reaction of hydrogen with another substance.

Chemical reaction in which an element gains an electron (has a decrease in positive valence).

(computer science)

Any process by which data are condensed, such as changing the encoding to eliminate redundancy, extracting significant details from the data and eliminating the rest, or choosing every second or third out of the totality of available points.

(geology)

The lowering of a land surface by erosion.

(navigation)

The process of substituting for an observed value one derived therefrom, as the calculation of the corresponding meridian altitude from an observation of a celestial body near the meridian, or the derivation from a celestial observation of the information needed for establishing a line of position.

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reduction - (Or "contraction") The process of transforming an expression according to certain reduction rules. The most important forms are beta reduction (application of a lambda abstraction to one or more argument expressions) and delta reduction (application of a mathematical function to the required number of arguments). An evaluation strategy (or reduction strategy), determines which part of an expression (which redex) to reduce first. There are many such strategies. See graph reduction, string reduction, normal order reduction, applicative order reduction, parallel reduction, alpha conversion, beta conversion, delta conversion, eta conversion.