-1/2 a^{a0,v0}_{c0,a1} b^{a2,v2}_{c1,c2} c^{v1}_{v2} gamma1^{a1}_{a2} a+(c0) a+(c1) a+(c2) a-(v1) a-(v0) a-(a0)
+1/2 a^{a0,v2}_{c0,a1} b^{a2,v0}_{c1,c2} c^{v1}_{v2} gamma1^{a1}_{a2} a+(c0) a+(c1) a+(c2) a-(v1) a-(v0) a-(a0)