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