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