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