-a^{c1,a2}_{c0,a0} b^{c2}_{c4} c^{c3,c4}_{a1,a3} eta1^{a3}_{a2} a+(c0) a+(a0) a+(a1) a-(c3) a-(c2) a-(c1)
+1/2 a^{c0,a1}_{c2,a0} b^{c1}_{c3} c^{c2,c3}_{a2,a3} a+(a0) a+(a2) a+(a3) a-(a1) a-(c1) a-(c0)
-1/2 a^{c0,a1}_{c2,a0} b^{c2}_{c3} c^{c1,c3}_{a2,a3} a+(a0) a+(a2) a+(a3) a-(a1) a-(c1) a-(c0)
-a^{c0,a2}_{c2,a0} b^{c1}_{c3} c^{c2,c3}_{a1,a3} eta1^{a3}_{a2} a+(a0) a+(a1) a-(c1) a-(c0)
+a^{c0,a2}_{c2,a0} b^{c2}_{c3} c^{c1,c3}_{a1,a3} eta1^{a3}_{a2} a+(a0) a+(a1) a-(c1) a-(c0)
+a^{c0,a2}_{c4,a0} b^{c2}_{c1} c^{c3,c4}_{a1,a3} eta1^{a3}_{a2} a+(c1) a+(a0) a+(a1) a-(c3) a-(c2) a-(c0)
+1/2 a^{c0,a2}_{c4,a0} b^{c4}_{c1} c^{c2,c3}_{a1,a3} eta1^{a3}_{a2} a+(c1) a+(a0) a+(a1) a-(c3) a-(c2) a-(c0)