-1/2 a^{c0,a1}_{c5,a0} b^{c1}_{a2} c^{c4,c5}_{c2,c3} eta1^{a2}_{a1} a+(c2) a+(c3) a+(a0) a-(c4) a-(c1) a-(c0)
-1/4 a^{c0,a1}_{c5,a0} b^{c5}_{a2} c^{c3,c4}_{c1,c2} eta1^{a2}_{a1} a+(c1) a+(c2) a+(a0) a-(c4) a-(c3) a-(c0)