a^{v0}_{c0} b^{v1,v2}_{c1,a0} c^{a1}_{v2} gamma1^{a0}_{a1} a+(c0) a+(c1) a-(v1) a-(v0)
+1/2 a^{v2}_{c0} b^{v0,v1}_{c1,a0} c^{a1}_{v2} gamma1^{a0}_{a1} a+(c0) a+(c1) a-(v1) a-(v0)