X is said to have the homotopy extension property (HEP) if the following holds :-Given any map http://dientuvietnam...etex.cgi?F:X->Z and any homotopy http://dientuvietnam...i?[0,1]->Z , such that http://dientuvietnam...metex.cgi?d(x,0)=F|_{Y} there exits a homotopy http://dientuvietnam...i?[0,1]->Z such that http://dientuvietnam...ex.cgi?D(x,0}=F and
If X is an Euclidean neighborhood retracts (ENR) show that Y
X has HEP if and only if Y is a closed neiborhood retract in X .
Bài viết đã được chỉnh sửa nội dung bởi pizza: 14-11-2005 - 21:34
