Tightness of compact spaces is preserved by the t - equivalence relation
نویسنده
چکیده
We prove that if there is an open mapping from a subspace of Cp(X) onto Cp(Y ), then Y is a countable union of images of closed subspaces of finite powers of X under finite-valued upper semicontinuous mappings. This allows, in particular, to prove that if X and Y are t-equivalent compact spaces, then X and Y have the same tightness, and that, assuming 2 > c, if X and Y are t-equivalent compact spaces and X is sequential, then Y is sequential.
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تاریخ انتشار 2010