Let be a topological space, and let be the adjunction , where is a closed -ball (http://planetmath.org/StandardNBall) and is a continuous map, with is the -sphere considered as the boundary of . Then, we say that is obtained from by the attachment of a -cell, by the attaching map The image of in is called a closed -cell, and the image of the interior
of is the corresponding open -cell.
Note that for the above definition reduces to the statement that is the disjoint union of with a one-point space.
|Date of creation||2013-03-22 13:25:53|
|Last modified on||2013-03-22 13:25:53|
|Last modified by||yark (2760)|