cyclic covering
71Grushko theorem — In the mathematical subject of group theory, the Grushko theorem or the Grushko Neumann theorem is a theorem stating that the rank (that is, the smallest cardinality of a generating set) of a free product of two groups is equal to the sum of the… …
72Burau representation — In mathematics the Burau representation is a representation of the braid groups. The Burau representation has two common and near equivalent formulations, the reduced and unreduced Burau representations. Definition Consider the braid group B n to …
73Botswana — /bot swah neuh/, n. a republic in S Africa: formerly a British protectorate; gained independence 1966; member of the Commonwealth of Nations. 1,500,765; 275,000 sq. mi. (712,250 sq. km). Cap.: Gaborone. Formerly, Bechuanaland. * * * Botswana… …
74Germany — /jerr meuh nee/, n. a republic in central Europe: after World War II divided into four zones, British, French, U.S., and Soviet, and in 1949 into East Germany and West Germany; East and West Germany were reunited in 1990. 84,068,216; 137,852 sq.… …
75Swaziland — /swah zee land /, n. a kingdom in SE Africa between S Mozambique and the E Republic of South Africa: formerly a British protectorate. 1,031,600; 6704 sq. mi. (17,363 sq. km). Cap.: Mbabane. * * * Swaziland Introduction Swaziland Background:… …
76Islamic arts — Visual, literary, and performing arts of the populations that adopted Islam from the 7th century. Islamic visual arts are decorative, colourful, and, in religious art, nonrepresentational; the characteristic Islamic decoration is the arabesque.… …
77Business and Industry Review — ▪ 1999 Introduction Overview Annual Average Rates of Growth of Manufacturing Output, 1980 97, Table Pattern of Output, 1994 97, Table Index Numbers of Production, Employment, and Productivity in Manufacturing Industries, Table (For Annual… …
78motion picture, history of the — Introduction history of the medium from the 19th century to the present. Early years, 1830–1910 Origins The illusion of motion pictures is based on the optical phenomena known as persistence of vision and the phi phenomenon. The first …
79Sildenafil — Viagra redirects here. For other uses, see Viagra (disambiguation). Sildenafil …
80Symmetry — For other uses, see Symmetry (disambiguation) …
