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