a^{c0}_{c2} b^{c1,a1}_{a0,v0} c^{c2}_{a2} eta1^{a2}_{a1} a+(a0) a+(v0) a-(c1) a-(c0)
-a^{c0}_{c2} b^{c2,a1}_{a0,v0} c^{c1}_{a2} eta1^{a2}_{a1} a+(a0) a+(v0) a-(c1) a-(c0)