{ "id": "math/0512110", "version": "v4", "published": "2005-12-05T22:31:32.000Z", "updated": "2006-03-07T11:16:13.000Z", "title": "Computably Based Locally Compact Spaces", "authors": [ "Paul Taylor" ], "comment": "70pp, LaTeX2e, uses diagrams.sty; Accepted for \"Logical Methods in Computer Science\" LMCS-2004-19; see http://www.cs.man.ac.uk/~pt/ASD for related papers. ACM-class: F.4.1", "journal": "LMCS 1 (4:1) 2006", "doi": "10.2168/LMCS-1(4:1)2006", "categories": [ "math.GN", "cs.LO", "math.CT" ], "abstract": "ASD (Abstract Stone Duality) is a re-axiomatisation of general topology in which the topology on a space is treated, not as an infinitary lattice, but as an exponential object of the same category as the original space, with an associated lambda-calculus. In this paper, this is shown to be equivalent to a notion of computable basis for locally compact sober spaces or locales, involving a family of open subspaces and accompanying family of compact ones. This generalises Smyth's effectively given domains and Jung's strong proximity lattices. Part of the data for a basis is the inclusion relation of compact subspaces within open ones, which is formulated in locale theory as the way-below relation on a continuous lattice. The finitary properties of this relation are characterised here, including the Wilker condition for the cover of a compact space by two open ones. The real line is used as a running example, being closely related to Scott's domain of intervals. ASD does not use the category of sets, but the full subcategory of overt discrete objects plays this role; it is an arithmetic universe (pretopos with lists). In particular, we use this subcategory to translate computable bases for classical spaces into objects in the ASD calculus.", "revisions": [ { "version": "v4", "updated": "2006-03-07T11:16:13.000Z" } ], "analyses": { "subjects": [ "54D45", "03D45", "06B35", "54D30", "68N18" ], "keywords": [ "locally compact spaces", "jungs strong proximity lattices", "overt discrete objects plays", "locally compact sober spaces", "abstract stone duality" ], "tags": [ "journal article" ], "note": { "typesetting": "LaTeX", "pages": 70, "language": "en", "license": "arXiv", "status": "editable" } } }