1/2 a^{c0,a0,a1}_{} b^{c2}_{c1,a2,a3} eta1^{a3}_{a1} eta1^{a2}_{a0} a+(c1) a-(c2) a-(c0)
+1/4 a^{c0,a0,a1}_{} b^{c2}_{c1,a2,a3} lambda2^{a2,a3}_{a0,a1} a+(c1) a-(c2) a-(c0)
-a^{c0,a0,a2}_{} b^{c2}_{c1,a1,a3} eta1^{a3}_{a2} a+(c1) a+(a1) a-(a0) a-(c2) a-(c0)