1/2 a^{a0,a1}_{c0,v0} b^{c1,c2}_{c3,a2} c^{c3}_{v1} eta1^{a2}_{a1} a+(c0) a+(v0) a+(v1) a-(a0) a-(c2) a-(c1)
+1/2 a^{a0,a1}_{c1,v0} b^{c0,c1}_{c2,a2} c^{c2}_{v1} a+(a2) a+(v0) a+(v1) a-(a1) a-(a0) a-(c0)
-a^{a0,a1}_{c1,v0} b^{c0,c1}_{c2,a2} c^{c2}_{v1} eta1^{a2}_{a1} a+(v0) a+(v1) a-(a0) a-(c0)
-1/2 a^{a0,a1}_{c3,v0} b^{c1,c2}_{c0,a2} c^{c3}_{v1} eta1^{a2}_{a1} a+(c0) a+(v0) a+(v1) a-(a0) a-(c2) a-(c1)
+a^{a0,a1}_{c3,v0} b^{c1,c3}_{c0,a2} c^{c2}_{v1} eta1^{a2}_{a1} a+(c0) a+(v0) a+(v1) a-(a0) a-(c2) a-(c1)