-a^{a1}_{c2} b^{c0}_{v0} c^{c1,c2}_{a0,a2} eta1^{a2}_{a1} a+(a0) a+(v0) a-(c1) a-(c0)
-1/2 a^{a1}_{c2} b^{c2}_{v0} c^{c0,c1}_{a0,a2} eta1^{a2}_{a1} a+(a0) a+(v0) a-(c1) a-(c0)