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A pointfree version of remainder preservation
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نویسنده
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Dube Themba ,Naidoo Inderasan
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منبع
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categories and general algebraic structures with applications - 2013 - دوره : 1 - شماره : 1 - صفحه:27 -58
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چکیده
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Recall that a continuous function f: x→ y between tychono spaces is proper if and only if the stone extension f^β : βx→ βy takes remainder to remainder, in the sense that f^β[βx-x] ⫃ βy-y . we introduce the notion of taking remainder to remainder to frames, and, using it, we defne a frame homomorphism h: l→ m to be β-proper, λ-proper or -proper in case the lifted homomorphism h^β: βl →βm, h : λl → λm or h: vl→ vm takes remainder to remainder. these turn out to be weaker forms of properness. indeed, every proper homomorphism is β-proper, every β-proper homomorphism is v-proper, and λ- properness is equivalent to -properness. a characterization of λ-proper maps in terms of pointfree rings of continuous functions is that they are precisely those whose induced ring homomorphisms contract free maximal ideals to free prime ideals.
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کلیدواژه
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frame ,remainder preservation ,Stone-Cech compactication ,regular Lindelof core- ection ,realcompact coreection ,proper map ,lax proper map
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آدرس
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University of South Africa, Department of Mathematical Sciences, South Africa, University of South Africa, Department of Mathematical Sciences, South Africa
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Authors
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