-1/2 a^{v0}_{a0} b^{a2,a3}_{a1,v0} c^{}_{} lambda2^{a0,a1}_{a2,a3}
+1/2 a^{v0}_{a0} b^{a2,a3}_{a1,v1} c^{}_{} lambda2^{a0,a1}_{a2,a3} a+(v1) a-(v0)
+a^{v0}_{a2} b^{a1,a3}_{a0,v0} c^{}_{} gamma1^{a2}_{a3} a+(a0) a-(a1)