-1/2 a^{a0,a1}_{c0,a3} b^{a2,a4}_{c1,c3} c^{c3}_{c2} gamma1^{a3}_{a4} a+(c0) a+(c1) a+(c2) a-(a2) a-(a1) a-(a0)
-1/4 a^{a0,a1}_{c3,a3} b^{a2,a4}_{c0,c1} c^{c3}_{c2} gamma1^{a3}_{a4} a+(c0) a+(c1) a+(c2) a-(a2) a-(a1) a-(a0)