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