Q[a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,u]
{
i*s+h*u,g*s+f*u,b*s-a*u,p*r+o*s,l*r+k*s,c*r-a*u,p*q+l*u,o*q+k*u,i*q+g*r,h*q+f*r,d*q-a*u,l*o-k*p,c*o+b*p,i*l-f*o,d*l+a*p,d*k+a*o,c*k+b*l,g*h-f*i,b*h+a*i,d*g+c*i,d*f+c*h,b*f+a*g
}