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