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This is a glossary of some terms used in the branch of mathematics known as topology. Although there is no absolute distinction between different areas of topology, the focus here is on general topology. The following definitions are also fundamental to algebraic topology, differential topology and geometric topology. See the article on topological spaces for basic definitions and examples, and see the article on topology for a brief history and description of the subject area. See Naive set theory, Axiomatic set theory, and Function for definitions concerning sets and functions. The following articles may also be useful. These either contain specialised vocabulary within general topology or provide more detailed expositions of the definitions given below. The list of general topology topics and the list of examples in general topology will also be very helpful. * Compact space * Connected space * Continuity * Metric space * Separated sets * Separation axiom * Topological space * Uniform space All spaces in this glossary are assumed to be topological spaces unless stated otherwise. __NOTOC__ == A == ;Absolutely closed: See ''H-closed'' ;Accessible: See . ;Accumulation point: See limit point. ;Alexandrov topology: The topology of a space ''X'' is an Alexandrov topology (or is finitely generated) if arbitrary intersections of open sets in ''X'' are open, or equivalently, if arbitrary unions of closed sets are closed, or, again equivalently, if the open sets are the upper sets of a poset.〔Vickers (1989) p.22〕 ;Almost discrete: A space is almost discrete if every open set is closed (hence clopen). The almost discrete spaces are precisely the finitely generated zero-dimensional spaces. ;Approach space: An approach space is a generalization of metric space based on point-to-set distances, instead of point-to-point. 抄文引用元・出典: フリー百科事典『 ウィキペディア(Wikipedia)』 ■ウィキペディアで「Glossary of topology」の詳細全文を読む スポンサード リンク
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