Function: coredisc
Section: number_theoretical
C-Name: coredisc0
Prototype: GD0,L,
Help: coredisc(n,{flag=0}): discriminant of the quadratic field Q(sqrt(n)).
 If (optional) flag is non-null, output a two-component row vector [d,f],
 where d is the discriminant of the quadratic field Q(sqrt(n)) and n=df^2. f
 may be a half integer

