Let f : X → Y be a mapping from set X to set Y. That is, suppose that for each point x in X there corresponds a point f ( x ) in Y. If both sets X and Y have a structure that can be expressed by concepts such as "close" or "approaching", i.e. a topological structure, then we can define the concept that the mapping f is continuous at point a in X. In other words, we define it by the condition that "if point x in X is close to a , then f ( x ) will be as close as possible to f ( a )." Then, by defining it as "if f is continuous at each point in X , then the mapping f : X → Y is continuous," we obtain the concept of a continuous mapping. Source: Heibonsha World Encyclopedia, 2nd Edition Information |
f:X→Yを集合Xから集合Yへの写像とする。すなわちXの各点xに対しYの点f(x)が対応しているとする。もし集合X,Yのいずれもが“近い”とか“近づく”といった概念で表される構造,すなわち位相構造を備えていれば,写像fがXの点aで連続であるという概念が定義できる。すなわち,〈Xの点xがaに近くなれば,f(x)がf(a)にいくらでも近くなる〉という条件によってそれを定義するのである。そして,〈fがXの各点で連続であるとき,写像f:X→Yは連続である〉と定義することにより,連続写像という概念が得られる。
出典 株式会社平凡社世界大百科事典 第2版について 情報 |
<<: Continuous steelmaking process
…The ruins of a city located about 20 km west of ...
1854‐1928 A modern Indian religious and social ref...
During the Qing Dynasty in China, among the young...
...A marine fish of the Scombridae family in the ...
A former town in Nishiyatsushiro County in the sou...
...In addition to these characteristics, the abra...
...A bribery case involving the acquisition of 14...
...By the second half of the 17th century, the tr...
A city in eastern Massachusetts, USA. It is locate...
…It was discovered by R. Hooke. The limit of stre...
?-? A merchant in the mid-Edo period. He was one ...
A group of plant pigments, referring to the pigme...
Roman statesman of the 1st century BC. He married ...
...In addition, there are tentacles, papillae, do...
…A general term for arthropods belonging to the C...