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