-1/4 a^{a1,a2}_{a0,v0} b^{c1}_{c0} c^{c2,c3}_{a3,v1} lambda2^{a0,a3}_{a1,a2} a+(c0) a+(v0) a+(v1) a-(c3) a-(c2) a-(c1)
+a^{a1,a2}_{a0,v0} b^{c0}_{c2} c^{c1,c2}_{a3,v1} eta1^{a3}_{a2} a+(a0) a+(v0) a+(v1) a-(a1) a-(c1) a-(c0)
-1/2 a^{a1,a2}_{a0,v0} b^{c0}_{c2} c^{c1,c2}_{a3,v1} lambda2^{a0,a3}_{a1,a2} a+(v0) a+(v1) a-(c1) a-(c0)