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