1/4 a^{c1,c2}_{c0,c3} b^{c3}_{c4} c^{c4,a2}_{a0,a1} a+(c0) a+(a0) a+(a1) a-(a2) a-(c2) a-(c1)
+1/4 a^{c0,c1}_{c3,c4} b^{c3}_{c2} c^{c4,a2}_{a0,a1} a+(c2) a+(a0) a+(a1) a-(a2) a-(c1) a-(c0)