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proof, in mathematics

(Encyclopedia)proof, in mathematics, finite sequence of propositions each of which is either an axiom or follows from preceding propositions by one of the rules of logical inference (see symbolic logic). Mathematic...

archangel, in religion

(Encyclopedia)archangel ärkˈānjəl [key], chief angel. They are four to seven in number. Sometimes specific functions are ascribed to them. The four best known in Christian tradition are Michael, Gabriel, Raphae...

bias, in electricity

(Encyclopedia)bias, a voltage, current, or other input applied to a device or system as a reference or to set its conditions of operation. A bias is usually steady but may vary with time, usually within a fixed and...

rye, in botany

(Encyclopedia)rye, cereal grain of the family Poaceae (grass family). The grain, Secale cereale, is important chiefly in Central and N Europe. It seems to have been domesticated later than wheat and other staple gr...

cypress, in botany

(Encyclopedia)cypress, common name for members of the Cupressaceae, a widely distributed family of coniferous shrubs and trees, several yielding valuable timber. The major genera are Juniperus (juniper), Thuja (arb...

induction, in logic

(Encyclopedia)induction, in logic, a form of argument in which the premises give grounds for the conclusion but do not necessitate it. Induction is contrasted with deduction, in which true premises do necessitate t...

mesquite, in botany

(Encyclopedia)mesquite mĭskētˈ, mĕsˈkēt [key], any plant of the genus Prosopis, leguminous spiny trees or shrubs of the family Leguminosae (pulse family), native to tropical and subtropical regions. The seed ...

cone, in mathematics

(Encyclopedia)CE5 Cone cone or conical surface, in mathematics, surface generated by a moving line (the generator) that passes through a given fixed point (the vertex) and continually intersects a given fixed c...

ether, in chemistry

(Encyclopedia)CE5 Ethers ether, any of a number of organic compounds whose molecules contain two hydrocarbon groups joined by single bonds to an oxygen atom. The most common of these compounds is ethyl ether, C...

harrow, in agriculture

(Encyclopedia)harrow, farm implement, consisting of a wooden or metal framework bearing metal disks, teeth, or sharp projecting points, called tines, which is dragged over plowed land to pulverize the clods of eart...