{ "id": "1901.10054", "version": "v1", "published": "2019-01-18T20:15:20.000Z", "updated": "2019-01-18T20:15:20.000Z", "title": "On the cardinality of $π(δ)$", "authors": [ "Attila Losonczi" ], "categories": [ "math.GN" ], "abstract": "We prove that the cardinality of transitive quasi-uniformities in a quasi-proximity class is at least $2^{2^{\\aleph_0}}$ if there exist at least two transitive quasi-uniformities in the class. The transitive elements of $\\pi(\\delta)$ are characterized if ${\\cal V}_{\\delta}$ is transitive, and in this case we give a condition when there exists a unique transitive quasi-uniformity in $\\pi(\\delta)$.", "revisions": [ { "version": "v1", "updated": "2019-01-18T20:15:20.000Z" } ], "analyses": { "keywords": [ "cardinality", "quasi-proximity class", "unique transitive quasi-uniformity" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }