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