送交者: fagus 于 2005-3-04, 18:31:44:

回答: hehe, what about measurable space? do you know what the space time continum? 由 xj 于 2005-3-04, 17:22:40:

(R)是一维连续空间,(Z)是一维离散(不连续)空间.
(R,R)是二维连续空间,(R,Z),(Z,R),(Z,Z)都是二维离散空间.

加跟贴