And what does "A+B proper" means?
Hi, I have the follow question:
Probe that, if and are closet sets in , and the restriction of the map to is proper, then is closed.
Def: Let be closet subsets of , We shall say the restriction of the map
to is proper if, for any , there is such that and imply that for .
Thanks for you help.
PS: edited: in the first line, change: proper to closed. Tnaks InvisibleMan