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