1/2 a^{c1,a1}_{c0,a0} b^{v0}_{a2} c^{c3,c4}_{c2,v0} eta1^{a2}_{a1} a+(c0) a+(c2) a+(a0) a-(c4) a-(c3) a-(c1)
-a^{c0,a1}_{c3,a0} b^{v0}_{a2} c^{c2,c3}_{c1,v0} a+(c1) a+(a0) a+(a2) a-(a1) a-(c2) a-(c0)
+a^{c0,a1}_{c3,a0} b^{v0}_{a2} c^{c2,c3}_{c1,v0} eta1^{a2}_{a1} a+(c1) a+(a0) a-(c2) a-(c0)
-a^{c0,a1}_{c3,a0} b^{v0}_{a2} c^{c2,c3}_{c1,v1} eta1^{a2}_{a1} a+(c1) a+(a0) a+(v1) a-(v0) a-(c2) a-(c0)