1/2 a^{a0}_{c3} b^{c0,c3}_{a2,v0} c^{a1,a3}_{c1,c2} gamma1^{a2}_{a3} a+(c1) a+(c2) a+(v0) a-(a1) a-(a0) a-(c0)
-1/4 a^{a2}_{c3} b^{c0,c3}_{a3,v0} c^{a0,a1}_{c1,c2} eta1^{a3}_{a2} a+(c1) a+(c2) a+(v0) a-(a1) a-(a0) a-(c0)