1/4 a^{a0,a1}_{c3,v0} b^{c3,v1}_{c0,a3} c^{a2,a4}_{c1,c2} gamma1^{a3}_{a4} a+(c0) a+(c1) a+(c2) a+(v0) a-(v1) a-(a2) a-(a1) a-(a0)
-1/4 a^{a0,a3}_{c3,v0} b^{c3,v1}_{c0,a4} c^{a1,a2}_{c1,c2} eta1^{a4}_{a3} a+(c0) a+(c1) a+(c2) a+(v0) a-(v1) a-(a2) a-(a1) a-(a0)