1/4 a^{v2}_{a0} b^{c0,a1}_{v0,v1} c^{c2,c3}_{c1,v2} gamma1^{a0}_{a1} a+(c1) a+(v0) a+(v1) a-(c3) a-(c2) a-(c0)
-1/2 a^{v2}_{a0} b^{c0,a1}_{v0,v2} c^{c2,c3}_{c1,v1} gamma1^{a0}_{a1} a+(c1) a+(v0) a+(v1) a-(c3) a-(c2) a-(c0)