-1/8 a^{a1}_{c0} b^{a0,a4}_{a2,a3} c^{c3,c4}_{c1,c2} lambda2^{a2,a3}_{a1,a4} a+(c0) a+(c1) a+(c2) a-(a0) a-(c4) a-(c3)
+1/4 a^{a1}_{c3} b^{a0,a4}_{a2,a3} c^{c2,c3}_{c0,c1} lambda2^{a2,a3}_{a1,a4} a+(c0) a+(c1) a-(a0) a-(c2)
+1/4 a^{a3}_{c3} b^{a1,a2}_{a0,a4} c^{c2,c3}_{c0,c1} eta1^{a4}_{a3} a+(c0) a+(c1) a+(a0) a-(a2) a-(a1) a-(c2)