Function: quadhilbert
Section: number_theoretical
C-Name: quadhilbert
Prototype: Gp
Help: quadhilbert(D): relative equation for the Hilbert class field
 of the quadratic field of discriminant D (which can also be a bnf).
Doc: relative equation defining the
 \idx{Hilbert class field} of the quadratic field of discriminant $D$.

 If $D < 0$, uses complex multiplication (\idx{Schertz}'s variant).

 If $D > 0$ \idx{Stark units} are used and (in rare cases) a
 vector of extensions may be returned whose compositum is the requested class
 field. See \kbd{bnrstark} for details.
