1/4 a^{a0,v2}_{v0,v1} b^{c0,c1}_{a1,v2} c^{a2}_{c2} gamma1^{a1}_{a2} a+(c2) a+(v0) a+(v1) a-(a0) a-(c1) a-(c0)
+1/4 a^{a1,v2}_{v0,v1} b^{c0,c1}_{a2,v2} c^{a0}_{c2} eta1^{a2}_{a1} a+(c2) a+(v0) a+(v1) a-(a0) a-(c1) a-(c0)