1/2 a^{c1,a0}_{c0,v0} b^{v1,v2}_{a1,a2} c^{a3}_{c2} eta1^{a1}_{a0} gamma1^{a2}_{a3} a+(c0) a+(c2) a+(v0) a-(v2) a-(v1) a-(c1)
-1/4 a^{c1,a0}_{c0,v0} b^{v1,v2}_{a1,a2} c^{a3}_{c2} lambda2^{a1,a2}_{a0,a3} a+(c0) a+(c2) a+(v0) a-(v2) a-(v1) a-(c1)