@prefix psr: <http://data.loterre.fr/ark:/67375/PSR> .
@prefix skos: <http://www.w3.org/2004/02/skos/core#> .
@prefix dc: <http://purl.org/dc/terms/> .
@prefix xsd: <http://www.w3.org/2001/XMLSchema#> .

psr:-VLFHQ406-F
  skos:prefLabel "Boy's surface"@en, "surface de Boy"@fr ;
  skos:broader psr:-Q84CW10B-H, psr:-NW4SNZDH-0 ;
  skos:definition """In geometry, Boy's surface is an immersion of the real projective plane in 3-dimensional space found by Werner Boy in 1901. He discovered it on assignment from David Hilbert to prove that the projective plane could not be immersed in 3-space. Boy's surface was first parametrized explicitly by Bernard Morin in 1978. Another parametrization was discovered by Rob Kusner and Robert Bryant. Boy's surface is one of the two possible immersions of the real projective plane which have only a single triple point. 
<br/>(Wikipedia, The Free Encyclopedia, <a href="https://en.wikipedia.org/wiki/Boy%27s_surface">https://en.wikipedia.org/wiki/Boy%27s_surface</a>)"""@en, """La <b>surface de Boy</b>, du nom de Werner Boy, mathématicien ayant été le premier à imaginer son existence en 1902, est une immersion du plan projectif réel <span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\\\\displaystyle \\\\mathbb {P} ^{2}(\\\\mathbb {R} )}">
<br/>  <semantics>
<br/>    <mrow class="MJX-TeXAtom-ORD">
<br/>      <mstyle displaystyle="true" scriptlevel="0">
<br/>        <msup>
<br/>          <mrow class="MJX-TeXAtom-ORD">
<br/>            <mi mathvariant="double-struck">P</mi>
<br/>          </mrow>
<br/>          <mrow class="MJX-TeXAtom-ORD">
<br/>            <mn>2</mn>
<br/>          </mrow>
<br/>        </msup>
<br/>        <mo stretchy="false">(</mo>
<br/>        <mrow class="MJX-TeXAtom-ORD">
<br/>          <mi mathvariant="double-struck">R</mi>
<br/>        </mrow>
<br/>        <mo stretchy="false">)</mo>
<br/>      </mstyle>
<br/>    </mrow>
<br/>    <annotation encoding="application/x-tex">{\\\\displaystyle \\\\mathbb {P} ^{2}(\\\\mathbb {R} )}</annotation>
<br/>  </semantics>
<br/></math></span><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/f1749118356f155676025fbf8d0b5fb325b100ea" class="mwe-math-fallback-image-inline" aria-hidden="true" style="vertical-align: -0.838ex; width:5.962ex; height:3.176ex;" alt="{\\\\displaystyle \\\\mathbb {P} ^{2}(\\\\mathbb {R} )}"></span> dans l'espace usuel de dimension 3.
<br/>Le plan projectif <span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\\\\displaystyle \\\\mathbb {P} ^{2}(\\\\mathbb {R} )}">
<br/>  <semantics>
<br/>    <mrow class="MJX-TeXAtom-ORD">
<br/>      <mstyle displaystyle="true" scriptlevel="0">
<br/>        <msup>
<br/>          <mrow class="MJX-TeXAtom-ORD">
<br/>            <mi mathvariant="double-struck">P</mi>
<br/>          </mrow>
<br/>          <mrow class="MJX-TeXAtom-ORD">
<br/>            <mn>2</mn>
<br/>          </mrow>
<br/>        </msup>
<br/>        <mo stretchy="false">(</mo>
<br/>        <mrow class="MJX-TeXAtom-ORD">
<br/>          <mi mathvariant="double-struck">R</mi>
<br/>        </mrow>
<br/>        <mo stretchy="false">)</mo>
<br/>      </mstyle>
<br/>    </mrow>
<br/>    <annotation encoding="application/x-tex">{\\\\displaystyle \\\\mathbb {P} ^{2}(\\\\mathbb {R} )}</annotation>
<br/>  </semantics>
<br/></math></span><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/f1749118356f155676025fbf8d0b5fb325b100ea" class="mwe-math-fallback-image-inline" aria-hidden="true" style="vertical-align: -0.838ex; width:5.962ex; height:3.176ex;" alt="{\\\\displaystyle \\\\mathbb {P} ^{2}(\\\\mathbb {R} )}"></span> se définit comme l'espace quotient de <span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\\\\displaystyle \\\\mathbb {R} ^{3}\\\\setminus \\\\{0\\\\}}">
<br/>  <semantics>
<br/>    <mrow class="MJX-TeXAtom-ORD">
<br/>      <mstyle displaystyle="true" scriptlevel="0">
<br/>        <msup>
<br/>          <mrow class="MJX-TeXAtom-ORD">
<br/>            <mi mathvariant="double-struck">R</mi>
<br/>          </mrow>
<br/>          <mrow class="MJX-TeXAtom-ORD">
<br/>            <mn>3</mn>
<br/>          </mrow>
<br/>        </msup>
<br/>        <mo class="MJX-variant">∖<!-- ∖ --></mo>
<br/>        <mo fence="false" stretchy="false">{</mo>
<br/>        <mn>0</mn>
<br/>        <mo fence="false" stretchy="false">}</mo>
<br/>      </mstyle>
<br/>    </mrow>
<br/>    <annotation encoding="application/x-tex">{\\\\displaystyle \\\\mathbb {R} ^{3}\\\\setminus \\\\{0\\\\}}</annotation>
<br/>  </semantics>
<br/></math></span><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/009e183704a06599a53044fab6a2da8b1c79d6e2" class="mwe-math-fallback-image-inline" aria-hidden="true" style="vertical-align: -0.838ex; width:8.414ex; height:3.176ex;" alt="{\\\\displaystyle \\\\mathbb {R} ^{3}\\\\setminus \\\\{0\\\\}}"></span> par la relation d'équivalence qu'est la colinéarité.
<br/>La surface de Boy peut aussi être «&nbsp;vue&nbsp;» comme une sphère dont on a recollé deux à deux les points antipodaux, ou encore un disque dont on a recollé deux à deux les points diamétralement opposés de son bord. On peut également la construire en recollant le bord d'un disque sur le bord d'un ruban de Möbius. 
<br/>(Wikipedia, L'Encylopédie Libre, <a href="https://fr.wikipedia.org/wiki/Surface_de_Boy">https://fr.wikipedia.org/wiki/Surface_de_Boy</a>)"""@fr ;
  dc:created "2023-06-30"^^xsd:date ;
  dc:modified "2023-06-30"^^xsd:date ;
  skos:inScheme psr: ;
  skos:exactMatch <https://fr.wikipedia.org/wiki/Surface_de_Boy>, <https://en.wikipedia.org/wiki/Boy%27s_surface> ;
  a skos:Concept .

psr: a skos:ConceptScheme .
psr:-Q84CW10B-H
  skos:prefLabel "topological manifold"@en, "variété topologique"@fr ;
  a skos:Concept ;
  skos:narrower psr:-VLFHQ406-F .

psr:-NW4SNZDH-0
  skos:prefLabel "topologie géométrique"@fr, "geometric topology"@en ;
  a skos:Concept ;
  skos:narrower psr:-VLFHQ406-F .