# rigorous

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**Mathematical analysis**— Mathematical analysis, which mathematicians refer to simply as analysis, has its beginnings in the rigorous formulation of infinitesimal calculus. It is a branch of pure mathematics that includes the theories of differentiation, integration and… …122

**Hyperreal number**— *R redirects here. For R*, see Rockstar Games. The system of hyperreal numbers represents a rigorous method of treating the infinite and infinitesimal quantities. The hyperreals, or nonstandard reals, *R, are an extension of the real numbers R… …123

**Statistical ensemble (mathematical physics)**— In mathematical physics, especially as introduced into statistical mechanics and thermodynamics by J. Willard Gibbs in 1878, an ensemble (also statistical ensemble or thermodynamic ensemble)cite book |last=Kittel |first=Charles… …124

**United States Air Force Academy**— Infobox University name = United States Air Force Academy established = 1954 motto = type = Federal military academy head label = Superintendent head = Lt Gen John F. Regni city = Colorado Springs state = Colorado country = USA undergrad = 4,000… …125

**Mathematical proof**— In mathematics, a proof is a convincing demonstration (within the accepted standards of the field) that some mathematical statement is necessarily true.[1][2] Proofs are obtained from deductive reasoning, rather than from inductive or empirical… …126

**Ballistic vest**— A ballistic vest is an item of protective clothing that absorbs the impact from gun fired projectiles and shrapnel fragments from explosion. This protection is for the torso. Soft vests are made from many layers of woven or laminated fibers and… …127

**Lloyd's of London**— Not to be confused with Lloyds TSB or Lloyd s Register. Lloyd s redirects here. For other uses, see Lloyd This article is about the insurance market. For the film, see Lloyd s of London (film). Lloyd s Type Ins …128

**Infinitesimal**— Infinitesimals (from a 17th century Modern Latin coinage infinitesimus , originally referring to the infinite th member of a series) have been used to express the idea of objects so small that there is no way to see them or to measure them. For… …