1/4 a^{a2,a3}_{a0,a1} b^{}_{a4,a5} eta1^{a5}_{a3} eta1^{a4}_{a2} a+(a0) a+(a1)
+1/8 a^{a2,a3}_{a0,a1} b^{}_{a4,a5} lambda2^{a4,a5}_{a2,a3} a+(a0) a+(a1)
-1/2 a^{a2,a4}_{a0,a1} b^{}_{a3,a5} eta1^{a5}_{a4} a+(a0) a+(a1) a+(a3) a-(a2)
-1/2 a^{a3,a4}_{a0,a2} b^{}_{a1,a5} lambda2^{a2,a5}_{a3,a4} a+(a0) a+(a1)