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