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