-1/2 a^{v1,v2}_{c2,v0} b^{c0}_{a1} c^{c2,a2}_{c1,a0} gamma1^{a1}_{a2} a+(c1) a+(a0) a+(v0) a-(v2) a-(v1) a-(c0)
+1/2 a^{v1,v2}_{c2,v0} b^{c2}_{a1} c^{c1,a2}_{c0,a0} gamma1^{a1}_{a2} a+(c0) a+(a0) a+(v0) a-(v2) a-(v1) a-(c1)