1/2 a^{}_{c0,a0} b^{c0,a1}_{v0,v1} a+(a0) a+(v0) a+(v1) a-(a1)
+1/2 a^{}_{c0,a0} b^{c0,a1}_{v0,v1} gamma1^{a0}_{a1} a+(v0) a+(v1)
+1/2 a^{}_{c0,a0} b^{c1,a1}_{v0,v1} gamma1^{a0}_{a1} a+(c0) a+(v0) a+(v1) a-(c1)