1/8 a^{a1,a2}_{c0,a0} b^{c1}_{a3} c^{v0,v1}_{c2,c3} lambda2^{a0,a3}_{a1,a2} a+(c0) a+(c2) a+(c3) a-(v1) a-(v0) a-(c1)
-1/4 a^{a1,a2}_{c2,a0} b^{c2}_{a3} c^{v0,v1}_{c0,c1} eta1^{a3}_{a2} a+(c0) a+(c1) a+(a0) a-(v1) a-(v0) a-(a1)
+1/8 a^{a1,a2}_{c2,a0} b^{c2}_{a3} c^{v0,v1}_{c0,c1} lambda2^{a0,a3}_{a1,a2} a+(c0) a+(c1) a-(v1) a-(v0)