1/8 a^{a0}_{c0} b^{a1,a2}_{c3,c4} c^{c3,c4}_{c1,c2} a+(c0) a+(c1) a+(c2) a-(a2) a-(a1) a-(a0)
-1/4 a^{a0}_{c3} b^{a1,a2}_{c0,c4} c^{c3,c4}_{c1,c2} a+(c0) a+(c1) a+(c2) a-(a2) a-(a1) a-(a0)