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