2
$\begingroup$

can someone explain what the datum of a point $x$ on a scheme $X$ together with a tangent direction has to do with subschemes of length two concentrated in that point? It seems as if there would be some kind of correspondance I don't get.

Thanks a lot!

  • 1
    See exercise $I$$I$.2.8 of Hartshorne.2011-08-16

0 Answers 0