Exceptional curve of the first kind
= Exceptional curve of the first kind
{wiki=Exceptional_curve}
An exceptional curve of the first kind is a smooth rational curve $E$ on a smooth surface with $E^2=-1$. It can be contracted to a smooth point.
= Exceptional curve of the first kind
{wiki=Exceptional_curve}
An exceptional curve of the first kind is a smooth rational curve $E$ on a smooth surface with $E^2=-1$. It can be contracted to a smooth point.