mad mathematician
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I really don't understand why I didn't think about it while I learned UG topology back then.
The usual definition of Compactness is that every open cover of the compact space can be covered by a finite union from the arbitrary cover.
What about looking at a set that is covered by the intersection of a finite number of closed sets, from which we can cover by any number of closed sets' interesection?
I.e, if ##X=\cap_{i=1}^n F_i## then one can cover ##X## by an intersection of any number of closed sets.
Is there such a notion? is it too trivial? too strong?
The usual definition of Compactness is that every open cover of the compact space can be covered by a finite union from the arbitrary cover.
What about looking at a set that is covered by the intersection of a finite number of closed sets, from which we can cover by any number of closed sets' interesection?
I.e, if ##X=\cap_{i=1}^n F_i## then one can cover ##X## by an intersection of any number of closed sets.
Is there such a notion? is it too trivial? too strong?