1/2 a^{a0,a1}_{c0,v0} b^{a4,v1}_{a2,a3} c^{}_{} lambda2^{a2,a3}_{a1,a4} a+(c0) a+(v0) a-(v1) a-(a0)
+1/2 a^{a1,a2}_{c0,v0} b^{a0,v1}_{a3,a4} c^{}_{} eta1^{a4}_{a2} eta1^{a3}_{a1} a+(c0) a+(v0) a-(v1) a-(a0)
+1/4 a^{a1,a2}_{c0,v0} b^{a0,v1}_{a3,a4} c^{}_{} lambda2^{a3,a4}_{a1,a2} a+(c0) a+(v0) a-(v1) a-(a0)