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