install_github("YasuakiHonda","modular_j","main")$

asdf_load("modular_j")$

P[D](x)=product(x-j(a[i]),i,1,h[D]);

a:FindReducedQuadIrrD(-15);

FindClassNumberD(-15);

product(x-float_modular_j(a[i]),i,1,2);

aproxpoly:expand(%);

(cround(z):=round(realpart(z))+round(imagpart(z)), cround(coeff(aproxpoly,x,1)));

cround(coeff(aproxpoly,x,0));

x^2+%th(2)*x+%th(1);

FindClassPolyD(x,-15);