# Make+sheaves

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**Exact functor**— In homological algebra, an exact functor is a functor, from some category to another, which preserves exact sequences. Exact functors are very convenient in algebraic calculations, roughly speaking because they can be applied to presentations of… …112

**George Frisbie Hoar**— Infobox Congressman name =George Frisbie Hoar imagesize =200px state =Massachusetts district =8th 9th term start =March 4, 1869 term end =March 3, 1873 (8th) March 4, 1873 – March 3, 1877 (9th) preceded =John Denison Baldwin Alvah Crocker… …113

**Pullback (differential geometry)**— Suppose that φ : M → N is a smooth map between smooth manifolds M and N ; then there is an associated linear map from the space of 1 forms on N (the linear space of sections of the cotangent bundle) to the space of 1 forms on M . This linear map… …114

**Evaporative cooler**— An evaporative cooler, photographed in Rocky Ford, Colorado, used in the drier parts of the American West to provide economical cooling …115

**Spectral sequence**— In the area of mathematics known as homological algebra, especially in algebraic topology and group cohomology, a spectral sequence is a means of computing homology groups by taking successive approximations. Spectral sequences are a… …116

**Broad arrow**— A broad arrow or pheon is a type of arrow with a typically flat barbed head. It is a symbol used traditionally in heraldry, most notably in England, and later the United Kingdom to mark government property.Use in heraldryThe broad arrow as an… …117

**Charge (heraldry)**— For a more comprehensive list, see List of heraldic charges. Shield Field Supporter Supporter Motto (Scotland) …118

**Robinson R22**— Infobox Aircraft name=Robinson R22 caption= type=Light utility and trainer helicopter manufacturer=Robinson Helicopter Company designer=Frank Robinson first flight=1975 introduced=1979 retired= status= primary user= more users= produced= number… …119

**San Francisco cable car system**— Infobox nrhp2 | name =San Francisco Cable Cars nhl=yes caption = Powell Hyde line cable car passing by Lombard Street in Russian Hill location= 1390 Washington Street, San Francisco, California [http://www.nr.nps.gov/writeups/66000233.nl.pdf NHL… …120

**Ian Grojnowski**— is a mathematician working at the Department of Pure Mathematics and Mathematical Statistics of the University of Cambridge. Grojnowski was the first recipient of the Fröhlich Prize of the London Mathematical Society in 2004 for his work in… …