-1/16 a^{c0,c1}_{v0,v1} b^{v2,v3}_{c2,a1} c^{a3,a4}_{a0,a2} lambda2^{a1,a2}_{a3,a4} a+(c2) a+(a0) a+(v0) a+(v1) a-(v3) a-(v2) a-(c1) a-(c0)