1/2 a^{c0}_{a2} b^{a0,v0}_{c1,c2} c^{a1,a3}_{c3,v0} gamma1^{a2}_{a3} a+(c1) a+(c2) a+(c3) a-(a1) a-(a0) a-(c0)
+1/4 a^{c0}_{a2} b^{a3,v0}_{c1,c2} c^{a0,a1}_{c3,v0} gamma1^{a2}_{a3} a+(c1) a+(c2) a+(c3) a-(a1) a-(a0) a-(c0)