@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: a skos:ConceptScheme .
psr:-V0G085HP-P
  skos:prefLabel "differential geometry"@en, "géométrie différentielle"@fr ;
  a skos:Concept ;
  skos:narrower psr:-T8G7FCDP-G .

psr:-T8G7FCDP-G
  skos:definition """Le théorème des quatre sommets constitue un résultat remarquable de géométrie différentielle quant aux propriétés globales des courbes planes fermées. 
<br/>(Wikipedia, L'Encylopédie Libre, <a href="https://fr.wikipedia.org/wiki/Th%C3%A9or%C3%A8me_des_quatre_sommets">https://fr.wikipedia.org/wiki/Th%C3%A9or%C3%A8me_des_quatre_sommets</a>)"""@fr, """The four-vertex theorem of geometry states that the curvature along a simple, closed, smooth plane curve has at least four local extrema (specifically, at least two local maxima and at least two local minima). The name of the theorem derives from the convention of calling an extreme point of the curvature function a vertex. This theorem has many generalizations, including a version for space curves where a vertex is defined as a point of vanishing torsion. 
<br/>(Wikipedia, The Free Encyclopedia, <a href="https://en.wikipedia.org/wiki/Four-vertex_theorem">https://en.wikipedia.org/wiki/Four-vertex_theorem</a>)"""@en ;
  skos:exactMatch <https://en.wikipedia.org/wiki/Four-vertex_theorem>, <https://fr.wikipedia.org/wiki/Th%C3%A9or%C3%A8me_des_quatre_sommets> ;
  skos:broader psr:-V0G085HP-P ;
  dc:modified "2023-07-19"^^xsd:date ;
  skos:prefLabel "théorème des quatre sommets"@fr, "four-vertex theorem"@en ;
  skos:inScheme psr: ;
  dc:created "2023-07-19"^^xsd:date ;
  a skos:Concept ;
  skos:related psr:-WFQQ48RG-8 .

psr:-WFQQ48RG-8
  skos:prefLabel "plane curve"@en, "courbe plane"@fr ;
  a skos:Concept ;
  skos:related psr:-T8G7FCDP-G .