@prefix dcat: <http://www.w3.org/ns/dcat#> .
@prefix dct: <http://purl.org/dc/terms/> .
@prefix foaf: <http://xmlns.com/foaf/0.1/> .
@prefix vcard: <http://www.w3.org/2006/vcard/ns#> .
@prefix xsd: <http://www.w3.org/2001/XMLSchema#> .

<https://rec.harvest-normandie.data4citizen.com/dataset/oai-hal-hal-00852718v1> a dcat:Dataset ;
    dct:description """
              We give, for each countable ordinal $\\xi\\!\\geq\\! 1$, an example of a ${\\bf\\Delta}^0_2$ countable union of Borel rectangles that cannot be decomposed into countably many ${\\bf\\Pi}^0_\\xi$ rectangles. In fact, we provide a graph of a partial injection with disjoint domain and range, which is a difference of two closed sets, and which has no ${\\bf\\Delta}^0_\\xi$-measurable countable coloring.
            """ ;
    dct:identifier "hal-00852718" ;
    dct:issued "2026-05-10T01:44:39.405108"^^xsd:dateTime ;
    dct:language "en" ;
    dct:modified "2026-05-10T01:44:39.405113"^^xsd:dateTime ;
    dct:publisher <https://rec.harvest-normandie.data4citizen.com/organization/cce9db95-46d9-4dc2-84b6-764215d0a002> ;
    dct:title "Descriptive complexity of countable unions of Borel rectangles" ;
    dcat:contactPoint [ a vcard:Organization ;
            vcard:fn "CCSD" ] ;
    dcat:distribution <https://rec.harvest-normandie.data4citizen.com/dataset/oai-hal-hal-00852718v1/resource/285a53f9-0775-4976-8c56-1a2348b36f41> ;
    dcat:keyword "2010-msc-primary-03e15-secondary-54h05",
        "borel-chromatic-number",
        "borel-class",
        "coloring",
        "infoeu-reposemanticspreprint",
        "mathmath-gnmathematics-mathgeneral-topology-mathgn",
        "mathmath-lomathematics-mathlogic-mathlo",
        "preprints-working-papers-",
        "product",
        "rectangle" ;
    dcat:landingPage <https://hal.science/hal-00852718> .

<https://rec.harvest-normandie.data4citizen.com/dataset/oai-hal-hal-00852718v1/resource/285a53f9-0775-4976-8c56-1a2348b36f41> a dcat:Distribution ;
    dct:format "HTML" ;
    dct:issued "2026-05-10T01:44:39.407043"^^xsd:dateTime ;
    dct:modified "2026-05-10T01:44:39.395382"^^xsd:dateTime ;
    dct:title "Descriptive complexity of countable unions of Borel rectangles" ;
    dcat:accessURL <https://hal.science/hal-00852718> .

<https://rec.harvest-normandie.data4citizen.com/organization/cce9db95-46d9-4dc2-84b6-764215d0a002> a foaf:Agent ;
    foaf:name "test_moissonnage_selune" .

<https://hal.science/hal-00852718> a foaf:Document .