-1/2 a^{a0,v0}_{} b^{a3}_{a1,a2} lambda2^{a1,a2}_{a0,a3} a-(v0)
+a^{a2,v0}_{} b^{a1}_{a0,a3} eta1^{a3}_{a2} a+(a0) a-(v0) a-(a1)