Pointwise convergence and Ascoli theorems for nearness spaces

Authors

  • Zhanbo Yang University of the Incarnate Word

DOI:

https://doi.org/10.4995/agt.2009.1787

Keywords:

Nearness spaces, Subspace, Product space, Neighborhood system, Pointwise convergent, Ascoli’s theorem

Abstract

We first study subspaces and product spaces in the context of nearness spaces and prove that U-N spaces, C-N spaces, PN spaces and totally bounded nearness spaces are nearness hereditary; T-N spaces and compact nearness spaces are N-closed hereditary. We prove that N2 plus compact implies N-closed subsets. We prove that totally bounded, compact and N2 are productive. We generalize the concepts of neighborhood systems into the nearness spaces and prove that the nearness neighborhood systems are consistent with existing concepts of neighborhood systems in topological spaces, uniform spaces and proximity spaces respectively when considered in the respective sub-categories. We prove that a net of functions is convergent under the pointwise convergent nearness structure if and only if its cross-section at each point is convergent. We have also proved two Ascoli-Arzelà type of theorems.

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Author Biography

Zhanbo Yang, University of the Incarnate Word

Department of Mathematical Sciences

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How to Cite

[1]
Z. Yang, “Pointwise convergence and Ascoli theorems for nearness spaces”, Appl. Gen. Topol., vol. 10, no. 1, pp. 49–68, Apr. 2009.

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Section

Regular Articles