-1/2 a^{}_{} b^{c0,a0}_{a1,v0} c^{a3,a4}_{a2,v1} lambda2^{a1,a2}_{a3,a4} a+(v0) a+(v1) a-(a0) a-(c0)
+a^{}_{} b^{c0,a2}_{a1,v0} c^{a0,a4}_{a3,v1} eta1^{a3}_{a2} gamma1^{a1}_{a4} a+(v0) a+(v1) a-(a0) a-(c0)
+a^{}_{} b^{c0,a2}_{a1,v0} c^{a0,a4}_{a3,v1} lambda2^{a1,a3}_{a2,a4} a+(v0) a+(v1) a-(a0) a-(c0)