-1/4 a^{a0}_{c0,c1,c2} b^{c2}_{a1,a2} a+(c0) a+(c1) a+(a1) a+(a2) a-(a0)
+1/2 a^{a1}_{c0,c1,c2} b^{c2}_{a0,a2} eta1^{a2}_{a1} a+(c0) a+(c1) a+(a0)
-1/6 a^{a1}_{c0,c1,c2} b^{c3}_{a0,a2} eta1^{a2}_{a1} a+(c0) a+(c1) a+(c2) a+(a0) a-(c3)