-1/2 a^{c0,a3}_{c2,a0} b^{c1,v0}_{a1,a2} c^{c2}_{a4} eta1^{a4}_{a3} a+(a0) a+(a1) a+(a2) a-(v0) a-(c1) a-(c0)
+1/2 a^{c0,a3}_{c2,a0} b^{c2,v0}_{a1,a2} c^{c1}_{a4} eta1^{a4}_{a3} a+(a0) a+(a1) a+(a2) a-(v0) a-(c1) a-(c0)
+a^{c0,a3}_{c2,a0} b^{c1,v0}_{a1,a4} c^{c2}_{a2} eta1^{a4}_{a3} a+(a0) a+(a1) a+(a2) a-(v0) a-(c1) a-(c0)
-a^{c0,a3}_{c2,a0} b^{c2,v0}_{a1,a4} c^{c1}_{a2} eta1^{a4}_{a3} a+(a0) a+(a1) a+(a2) a-(v0) a-(c1) a-(c0)