1/8 a^{v1,v2}_{c0,v0} b^{a0,a3}_{a1,a2} c^{a4,v3}_{c1,c2} lambda2^{a1,a2}_{a3,a4} a+(c0) a+(c1) a+(c2) a+(v0) a-(v3) a-(v2) a-(v1) a-(a0)