1/6 a^{c0,a1,a2}_{a0} b^{}_{c1,c2,c3,a3} eta1^{a3}_{a2} a+(c1) a+(c2) a+(c3) a+(a0) a-(a1) a-(c0)
-1/12 a^{c0,a1,a2}_{a0} b^{}_{c1,c2,c3,a3} lambda2^{a0,a3}_{a1,a2} a+(c1) a+(c2) a+(c3) a-(c0)