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