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