1/2 a^{v1,v2}_{a0,v0} b^{c1,c2}_{c0,a1} c^{a2}_{v2} gamma1^{a1}_{a2} a+(c0) a+(a0) a+(v0) a-(v1) a-(c2) a-(c1)
-1/2 a^{v1,v2}_{a1,v0} b^{c1,c2}_{c0,a0} c^{a2}_{v2} gamma1^{a1}_{a2} a+(c0) a+(a0) a+(v0) a-(v1) a-(c2) a-(c1)