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