1/4 a^{v0}_{a0} b^{v1,v2}_{c0,a3} c^{c0,a4}_{a1,a2} gamma1^{a3}_{a4} a+(a0) a+(a1) a+(a2) a-(v2) a-(v1) a-(v0)
-1/4 a^{v0}_{a3} b^{v1,v2}_{c0,a0} c^{c0,a4}_{a1,a2} gamma1^{a3}_{a4} a+(a0) a+(a1) a+(a2) a-(v2) a-(v1) a-(v0)