a^{c0}_{a0} b^{a2}_{c2} c^{c1,c2}_{a1,a3} eta1^{a3}_{a2} a+(a0) a+(a1) a-(c1) a-(c0)
-1/2 a^{c0}_{a2} b^{a3}_{c2} c^{c1,c2}_{a0,a1} gamma1^{a2}_{a3} a+(a0) a+(a1) a-(c1) a-(c0)