1/4 a^{a0,a1}_{c0,c1} b^{a4,v0}_{a2,a3} c^{v1}_{c2} lambda2^{a2,a3}_{a1,a4} a+(c0) a+(c1) a+(c2) a-(v1) a-(v0) a-(a0)
+1/4 a^{a1,a2}_{c0,c1} b^{a0,v0}_{a3,a4} c^{v1}_{c2} eta1^{a4}_{a2} eta1^{a3}_{a1} a+(c0) a+(c1) a+(c2) a-(v1) a-(v0) a-(a0)
+1/8 a^{a1,a2}_{c0,c1} b^{a0,v0}_{a3,a4} c^{v1}_{c2} lambda2^{a3,a4}_{a1,a2} a+(c0) a+(c1) a+(c2) a-(v1) a-(v0) a-(a0)