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