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