1/2 a^{a0,a1}_{c0,a2} b^{a3}_{c2} c^{c2,v1}_{c1,v0} gamma1^{a2}_{a3} a+(c0) a+(c1) a+(v0) a-(v1) a-(a1) a-(a0)
-1/2 a^{a0,a1}_{c2,a2} b^{a3}_{c0} c^{c2,v1}_{c1,v0} gamma1^{a2}_{a3} a+(c0) a+(c1) a+(v0) a-(v1) a-(a1) a-(a0)