import libfive as lv

def lv_coord():
        return lv.x(),lv.y(),lv.z()

def lv_sphere(c,r):
    return lv.sqrt(c[0]*c[0]+c[1]*c[1]+c[2]*c[2])-r

c = lv_coord()
s1=lv_sphere(c,1)

fn=30
fobj=frep(s1, [-4,-4,-4], [4,4,4],20);
output(fobj);