-1/4 a^{c2,v0}_{c0,c1} b^{a1,a2}_{c3,a0} c^{c3}_{v0} a+(c0) a+(c1) a+(a0) a-(a2) a-(a1) a-(c2)
+1/2 a^{c1,v0}_{c0,c3} b^{a1,a2}_{c2,a0} c^{c3}_{v0} a+(c0) a+(c2) a+(a0) a-(a2) a-(a1) a-(c1)