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