@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:-XMS86XF9-P
  skos:definition """In geometry, a <b>cissoid</b> ((from Ancient Greek <i> </i>κισσοειδής<i> (kissoeidēs)</i>&nbsp;'ivy-shaped') is a plane curve generated from two given curves <span class="texhtml"><i>C</i><sub>1</sub></span>, <span class="texhtml"><i>C</i><sub>2</sub></span> and a point <span class="texhtml mvar" style="font-style:italic;">O</span> (the <b>pole</b>). Let <span class="texhtml mvar" style="font-style:italic;">L</span> be a variable line passing through <span class="texhtml mvar" style="font-style:italic;">O</span> and intersecting <span class="texhtml"><i>C</i><sub>1</sub></span> at <span class="texhtml"><i>P</i><sub>1</sub></span> and <span class="texhtml"><i>C</i><sub>2</sub></span> at <span class="texhtml"><i>P</i><sub>2</sub></span>. Let <span class="texhtml mvar" style="font-style:italic;">P</span> be the point on <span class="texhtml mvar" style="font-style:italic;">L</span> so that <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 {\\\\overline {OP}}={\\\\overline {P_{1}P_{2}}}.}">
<br/>  <semantics>
<br/>    <mrow class="MJX-TeXAtom-ORD">
<br/>      <mstyle displaystyle="true" scriptlevel="0">
<br/>        <mrow class="MJX-TeXAtom-ORD">
<br/>          <mover>
<br/>            <mrow>
<br/>              <mi>O</mi>
<br/>              <mi>P</mi>
<br/>            </mrow>
<br/>            <mo accent="false">¯<!-- ¯ --></mo>
<br/>          </mover>
<br/>        </mrow>
<br/>        <mo>=</mo>
<br/>        <mrow class="MJX-TeXAtom-ORD">
<br/>          <mover>
<br/>            <mrow>
<br/>              <msub>
<br/>                <mi>P</mi>
<br/>                <mrow class="MJX-TeXAtom-ORD">
<br/>                  <mn>1</mn>
<br/>                </mrow>
<br/>              </msub>
<br/>              <msub>
<br/>                <mi>P</mi>
<br/>                <mrow class="MJX-TeXAtom-ORD">
<br/>                  <mn>2</mn>
<br/>                </mrow>
<br/>              </msub>
<br/>            </mrow>
<br/>            <mo accent="false">¯<!-- ¯ --></mo>
<br/>          </mover>
<br/>        </mrow>
<br/>        <mo>.</mo>
<br/>      </mstyle>
<br/>    </mrow>
<br/>    <annotation encoding="application/x-tex">{\\\\displaystyle {\\\\overline {OP}}={\\\\overline {P_{1}P_{2}}}.}</annotation>
<br/>  </semantics>
<br/></math></span><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/4d689c93129d7164afcc58abab79631cb1d725f1" class="mwe-math-fallback-image-inline" aria-hidden="true" style="vertical-align: -0.671ex; width:12.752ex; height:3.343ex;" alt="{\\\\displaystyle {\\\\overline {OP}}={\\\\overline {P_{1}P_{2}}}.}"></span> (There are actually two such points but <span class="texhtml mvar" style="font-style:italic;">P</span> is chosen so that <span class="texhtml mvar" style="font-style:italic;">P</span> is in the same direction from <span class="texhtml mvar" style="font-style:italic;">O</span> as <span class="texhtml"><i>P</i><sub>2</sub></span> is from <span class="texhtml"><i>P</i><sub>1</sub></span>.) Then the locus of such points <span class="texhtml mvar" style="font-style:italic;">P</span> is defined to be the cissoid of the curves <span class="texhtml"><i>C</i><sub>1</sub></span>, <span class="texhtml"><i>C</i><sub>2</sub></span> relative to <span class="texhtml mvar" style="font-style:italic;">O</span>. 
<br/>(Wikipedia, The Free Encyclopedia, <a href="https://en.wikipedia.org/wiki/Cissoid">https://en.wikipedia.org/wiki/Cissoid</a>)"""@en, """En géométrie, la <b>cissoïde</b>, ou <b>courbe cissoïdale</b> ou <b>cissoïdale</b>, de deux courbes (C<sub>1</sub>) et (C<sub>2</sub>) par rapport à un point fixe O est le lieu géométrique des points P tels que&nbsp;:
<br/>
<br/><dl><dd><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 {\\\\overrightarrow {OP}}={\\\\overrightarrow {OP_{1}}}+{\\\\overrightarrow {OP_{2}}}}">
<br/>  <semantics>
<br/>    <mrow class="MJX-TeXAtom-ORD">
<br/>      <mstyle displaystyle="true" scriptlevel="0">
<br/>        <mrow class="MJX-TeXAtom-ORD">
<br/>          <mover>
<br/>            <mrow>
<br/>              <mi>O</mi>
<br/>              <mi>P</mi>
<br/>            </mrow>
<br/>            <mo>→<!-- → --></mo>
<br/>          </mover>
<br/>        </mrow>
<br/>        <mo>=</mo>
<br/>        <mrow class="MJX-TeXAtom-ORD">
<br/>          <mover>
<br/>            <mrow>
<br/>              <mi>O</mi>
<br/>              <msub>
<br/>                <mi>P</mi>
<br/>                <mrow class="MJX-TeXAtom-ORD">
<br/>                  <mn>1</mn>
<br/>                </mrow>
<br/>              </msub>
<br/>            </mrow>
<br/>            <mo>→<!-- → --></mo>
<br/>          </mover>
<br/>        </mrow>
<br/>        <mo>+</mo>
<br/>        <mrow class="MJX-TeXAtom-ORD">
<br/>          <mover>
<br/>            <mrow>
<br/>              <mi>O</mi>
<br/>              <msub>
<br/>                <mi>P</mi>
<br/>                <mrow class="MJX-TeXAtom-ORD">
<br/>                  <mn>2</mn>
<br/>                </mrow>
<br/>              </msub>
<br/>            </mrow>
<br/>            <mo>→<!-- → --></mo>
<br/>          </mover>
<br/>        </mrow>
<br/>      </mstyle>
<br/>    </mrow>
<br/>    <annotation encoding="application/x-tex">{\\\\displaystyle {\\\\overrightarrow {OP}}={\\\\overrightarrow {OP_{1}}}+{\\\\overrightarrow {OP_{2}}}}</annotation>
<br/>  </semantics>
<br/></math></span><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/9ddc3ecd6fc0243ab82565c1a6429fdcc9b3a7cf" class="mwe-math-fallback-image-inline" aria-hidden="true" style="vertical-align: -0.671ex; margin-top: -0.4ex; width:18.652ex; height:4.176ex;" alt="{\\\\displaystyle {\\\\overrightarrow {OP}}={\\\\overrightarrow {OP_{1}}}+{\\\\overrightarrow {OP_{2}}}}"></span></dd></dl>
<br/>où P1 est un point de (C<sub>1</sub>) et P<sub>2</sub> un point de (C<sub>2</sub>), P<sub>1</sub> et P<sub>2</sub> étant alignés avec O. 
<br/>(Wikipedia, L'Encylopédie Libre, <a href="https://fr.wikipedia.org/wiki/Cisso%C3%AFde">https://fr.wikipedia.org/wiki/Cisso%C3%AFde</a>)"""@fr ;
  skos:exactMatch <https://fr.wikipedia.org/wiki/Cisso%C3%AFde>, <https://en.wikipedia.org/wiki/Cissoid> ;
  skos:inScheme psr: ;
  dc:modified "2023-08-01"^^xsd:date ;
  skos:prefLabel "cissoid"@en, "cissoïde"@fr ;
  skos:broader psr:-WFQQ48RG-8, psr:-QP0D47D3-D ;
  a skos:Concept .

psr: a skos:ConceptScheme .
psr:-QP0D47D3-D
  skos:prefLabel "courbe algébrique"@fr, "algebraic curve"@en ;
  a skos:Concept ;
  skos:narrower psr:-XMS86XF9-P .

psr:-WFQQ48RG-8
  skos:prefLabel "plane curve"@en, "courbe plane"@fr ;
  a skos:Concept ;
  skos:narrower psr:-XMS86XF9-P .