-1/4 a^{}_{c0,c1,c2,a0} b^{c2,a1,a2}_{} a+(c0) a+(c1) a+(a0) a-(a2) a-(a1)
-1/2 a^{}_{c0,c1,c2,a1} b^{c2,a0,a2}_{} gamma1^{a1}_{a2} a+(c0) a+(c1) a-(a0)
+1/6 a^{}_{c0,c1,c2,a1} b^{c3,a0,a2}_{} gamma1^{a1}_{a2} a+(c0) a+(c1) a+(c2) a-(a0) a-(c3)