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