-1/2 a^{a0}_{c3} b^{c0,c3}_{a1,v0} c^{a2,v1}_{c1,c2} gamma1^{a1}_{a2} a+(c1) a+(c2) a+(v0) a-(v1) a-(a0) a-(c0)
-1/2 a^{a1}_{c3} b^{c0,c3}_{a2,v0} c^{a0,v1}_{c1,c2} eta1^{a2}_{a1} a+(c1) a+(c2) a+(v0) a-(v1) a-(a0) a-(c0)