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