@prefix psr: <http://data.loterre.fr/ark:/67375/PSR> .
@prefix skos: <http://www.w3.org/2004/02/skos/core#> .

psr:-TX92VB3N-7
  skos:prefLabel "differential geometry of surfaces"@en, "géométrie différentielle des surfaces"@fr ;
  a skos:Concept ;
  skos:narrower psr:-TH0GT9VF-6 .

psr: a skos:ConceptScheme .
psr:-TH0GT9VF-6
  skos:definition """In mathematics, a tangent vector is a vector that is tangent to a curve or surface at a given point. Tangent vectors are described in the differential geometry of curves in the context of curves in <b>R</b><sup><i>n</i></sup>. More generally, tangent vectors are elements of a tangent space of a differentiable manifold. Tangent vectors can also be described in terms of germs. Formally, a tangent vector at the point x is a linear derivation of the algebra defined by the set of germs at <i>x</i>. 
<br/>(Wikipedia, The Free Encyclopedia, <a href="https://en.wikipedia.org/wiki/Tangent_vector">https://en.wikipedia.org/wiki/Tangent_vector</a>)"""@en ;
  a skos:Concept ;
  skos:inScheme psr: ;
  skos:broader psr:-TX92VB3N-7 ;
  skos:prefLabel "tangent vector"@en, "vecteur tangent"@fr ;
  skos:exactMatch <https://en.wikipedia.org/wiki/Tangent_vector> .