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