a^{c1,a2}_{c0,a0} b^{v0}_{c3} c^{c2,c3}_{a1,a3} eta1^{a3}_{a2} a+(c0) a+(a0) a+(a1) a-(v0) a-(c2) a-(c1)
-1/2 a^{c0,a1}_{c1,a0} b^{v0}_{c2} c^{c1,c2}_{a2,a3} a+(a0) a+(a2) a+(a3) a-(v0) a-(a1) a-(c0)
-a^{c0,a2}_{c1,a0} b^{v0}_{c2} c^{c1,c2}_{a1,a3} eta1^{a3}_{a2} a+(a0) a+(a1) a-(v0) a-(c0)
-a^{c0,a2}_{c3,a0} b^{v0}_{c1} c^{c2,c3}_{a1,a3} eta1^{a3}_{a2} a+(c1) a+(a0) a+(a1) a-(v0) a-(c2) a-(c0)