Function: quaddisc
Section: number_theoretical
C-Name: quaddisc
Prototype: G
Help: quaddisc(x): discriminant of the quadratic field Q(sqrt(x)).
Doc: discriminant of the \'etale algebra $\Q(\sqrt{x})$, where $x\in\Q^*$.
 This is the same as \kbd{coredisc}$(d)$ where $d$ is the integer square-free
 part of $x$, so x=$d f^2$ with $f\in \Q^*$ and $d\in\Z$.
 This returns $0$ for $x = 0$, $1$ for $x$ square and the discriminant of the
 quadratic field $\Q(\sqrt{x})$ otherwise.
 \bprog
 ? quaddisc(7)
 %1 = 28
 ? quaddisc(-7)
 %2 = -7
 @eprog
