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