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Keywords:
projectively closed functor; finitary functor; functor of probability measures
Summary:
We introduce notions of projectively quotient, open, and closed functors. We give sufficient conditions for a functor to be projectively quotient. In particular, any finitary normal functor is projectively quotient. We prove that the sufficient conditions obtained are necessary for an arbitrary subfunctor $\Cal F$ of the functor $\Cal P$ of probability measures. At the same time, any ``good'' functor is neither projectively open nor projectively closed.
References:
[1] Shchepin E.V.: Functors and uncountable powers of compact spaces. Uspekhi Mat. Nauk 36 (1981), 3 3-62. MR 0622720
[2] Basmanov V.N.: Covariant functors, retracts and dimension. Dokl. Akad. Nauk USSR 271 (1983), 1033-1036. MR 0722013 | Zbl 0544.54007
[3] Chigogidze A.Ch.: Extension of normal functors. Vestnik Mosk. Univ. Ser. I Mat. Mekh. 6 (1984), 40-42. MR 0775298 | Zbl 0588.54016
[4] Fedorchuk V.V.: Probability measures in topology. Uspekhi Mat. Nauk 46 (1991), 1 41-80. MR 1109036 | Zbl 0735.54033
[5] Fedorchuk V.V., Filippov V.V.: General Topology: Basic Constructions. Moscow, Mosk. Gos. Univ., 1988. MR 1095303 | Zbl 0658.54001
[6] Engelking R.: General Topology. Warszawa, PWN, 1977. MR 0500780 | Zbl 0684.54001
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