ff(p,f) = ffgen(ffinit(p,f), 'a);
doell(a)= {
  my(e, P);
  e = ellinit([1,1,3,4,5]*a);
  P = random(e); [P, ellisoncurve(e,P)];
}
doff(p,f)=my(a = ff(p,f)); print(random(a)); doell(a);

setrand(1);
random(Mod(1,3))
doff(2,3)
doff(precprime(2^32), 3)
doff(nextprime(2^64), 3)
random(1.)
random(x^5*Mod(1,7))
