-1/4 a^{}_{} b^{a0,a2}_{v0,v1} c^{a1,a5}_{a3,a4} lambda2^{a3,a4}_{a2,a5} a+(v0) a+(v1) a-(a1) a-(a0)
+1/8 a^{}_{} b^{a2,a3}_{v0,v1} c^{a0,a1}_{a4,a5} eta1^{a5}_{a3} eta1^{a4}_{a2} a+(v0) a+(v1) a-(a1) a-(a0)
+1/16 a^{}_{} b^{a2,a3}_{v0,v1} c^{a0,a1}_{a4,a5} lambda2^{a4,a5}_{a2,a3} a+(v0) a+(v1) a-(a1) a-(a0)