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