1/4 a^{c1,c2}_{c0,c4} b^{c3,a2}_{a0,a1} c^{c4}_{a3} eta1^{a3}_{a2} a+(c0) a+(a0) a+(a1) a-(c3) a-(c2) a-(c1)
-1/4 a^{c1,c2}_{c0,c4} b^{c4,a2}_{a0,a1} c^{c3}_{a3} eta1^{a3}_{a2} a+(c0) a+(a0) a+(a1) a-(c3) a-(c2) a-(c1)
-1/4 a^{c0,c1}_{c2,c3} b^{c2,a2}_{a0,a1} c^{c3}_{a3} a+(a0) a+(a1) a+(a3) a-(a2) a-(c1) a-(c0)
+1/4 a^{c0,c1}_{c2,c3} b^{c2,a2}_{a0,a1} c^{c3}_{a3} eta1^{a3}_{a2} a+(a0) a+(a1) a-(c1) a-(c0)