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