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Problem 1.T in Kelley basically asks the reader to prove the following
version of the Brouwer Reduction Theorem. Consider a topological space
all of whose subspaces are Lindeloef. Let C be a collection of closed
sets with the property that if D is a countable chain (with respect to
inclusion) and a subfamily of C, then the intersection of D is in
C. Then for any A in C, there exists a minimal susbset B of A
which is also in C.
First question: My proof invokes Zorn's lemma. Have I relied on the
Axiom of Choice unnecessarily?
1.T(b) asks, in "an arbritrary topological space can any result of
this general sort be affirmed?" My answer is that one should remove the
countable condition on D from the above hypothesis. Is there a less
restrictive hypothesis for this "sort" of result?
[BTW, this is not HW.]
--
Stephen J. Herschkorn sjherschko@xxxxxxxxxxxx
Math Tutor on the Internet and in Central New Jersey and Manhattan
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