-1/2 a^{a0,a1}_{c2,v0} b^{c1,c2}_{c0,a2} c^{a3}_{v1} gamma1^{a2}_{a3} a+(c0) a+(v0) a+(v1) a-(a1) a-(a0) a-(c1)
-a^{a0,a2}_{c2,v0} b^{c1,c2}_{c0,a3} c^{a1}_{v1} eta1^{a3}_{a2} a+(c0) a+(v0) a+(v1) a-(a1) a-(a0) a-(c1)