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