Cone (topology)
(重定向自Reduced cone)

In topology, especially algebraic topology, the cone CX of a topological space X is the quotient space:
of the product of X with the unit interval I = [0, 1]. Intuitively we make X into a cylinder and collapse one end of the cylinder to a point.
If X sits inside Euclidean space, the cone on X is homeomorphic to the union of lines from X to another point. That is, the topological cone agrees with the geometric cone when defined. However, the topological cone construction is more general.