Tukey order, calibres and the rationals
نویسندگان
چکیده
One partially ordered set, Q, is a Tukey quotient of another, P – denoted P?TQ if there map ?:P?Q carrying cofinal sets to Q. Let X be space and denote by K(X) the set compact subsets X, inclusion. For certain separable metrizable spaces M, upper lower bounds K(M) are calculated. Results on invariants K(M)'s deduced. The structure all under ?T investigated. Particular emphasis placed position when M is: completely metrizable, rationals co-analytic or analytic.
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ژورنال
عنوان ژورنال: Annals of Pure and Applied Logic
سال: 2021
ISSN: ['0168-0072', '1873-2461']
DOI: https://doi.org/10.1016/j.apal.2020.102873