1/2 a^{c0}_{c2} b^{c1,v0}_{c3,a0} c^{c2,c3}_{a1,a2} a+(a0) a+(a1) a+(a2) a-(v0) a-(c1) a-(c0)
-1/2 a^{c0}_{c2} b^{c2,v0}_{c3,a0} c^{c1,c3}_{a1,a2} a+(a0) a+(a1) a+(a2) a-(v0) a-(c1) a-(c0)