1/2 a^{}_{a0} b^{a2,a3,v0}_{a1} lambda2^{a0,a1}_{a2,a3} a-(v0)
+a^{}_{a2} b^{a1,a3,v0}_{a0} gamma1^{a2}_{a3} a+(a0) a-(v0) a-(a1)