1/2 a^{v2}_{a1} b^{a0,a2}_{v0,v1} c^{c0}_{v2} gamma1^{a1}_{a2} a+(v0) a+(v1) a-(a0) a-(c0)
-a^{v2}_{a1} b^{a0,a2}_{v0,v2} c^{c0}_{v1} gamma1^{a1}_{a2} a+(v0) a+(v1) a-(a0) a-(c0)