-1/2 a^{v0}_{a0,a1,a2} b^{a3,v2}_{v1} gamma1^{a2}_{a3} a+(a0) a+(a1) a+(v1) a-(v2) a-(v0)
+1/6 a^{v1}_{a0,a1,a2} b^{a3,v0}_{v1} a+(a0) a+(a1) a+(a2) a-(v0) a-(a3)
-1/2 a^{v1}_{a0,a1,a2} b^{a3,v0}_{v1} gamma1^{a2}_{a3} a+(a0) a+(a1) a-(v0)