-1/4 a^{v1,v2}_{c3,v0} b^{c0}_{a0} c^{c3,a1}_{c1,c2} gamma1^{a0}_{a1} a+(c1) a+(c2) a+(v0) a-(v2) a-(v1) a-(c0)
+1/4 a^{v1,v2}_{c3,v0} b^{c3}_{a0} c^{c2,a1}_{c0,c1} gamma1^{a0}_{a1} a+(c0) a+(c1) a+(v0) a-(v2) a-(v1) a-(c2)