-1/4 a^{a2,a3}_{a0,a1} b^{c1,c2}_{c0,a4} c^{c4}_{c3} lambda2^{a1,a4}_{a2,a3} a+(c0) a+(c3) a+(a0) a-(c4) a-(c2) a-(c1)
+1/4 a^{a2,a3}_{a0,a1} b^{c0,c1}_{c3,a4} c^{c3}_{c2} eta1^{a4}_{a3} a+(c2) a+(a0) a+(a1) a-(a2) a-(c1) a-(c0)
-1/4 a^{a2,a3}_{a0,a1} b^{c0,c1}_{c3,a4} c^{c3}_{c2} lambda2^{a1,a4}_{a2,a3} a+(c2) a+(a0) a-(c1) a-(c0)