1/2 a^{v0,v1}_{c3,a0} b^{c1,c3}_{c0,a1} c^{a2}_{c2} gamma1^{a1}_{a2} a+(c0) a+(c2) a+(a0) a-(v1) a-(v0) a-(c1)
-1/2 a^{v0,v1}_{c3,a1} b^{c1,c3}_{c0,a0} c^{a2}_{c2} gamma1^{a1}_{a2} a+(c0) a+(c2) a+(a0) a-(v1) a-(v0) a-(c1)