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