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