1/4 a^{a0,a1}_{c0,c3} b^{c1,c2}_{v0,v1} c^{c3}_{a2} eta1^{a2}_{a1} a+(c0) a+(v0) a+(v1) a-(a0) a-(c2) a-(c1)
-1/2 a^{a0,a1}_{c0,c3} b^{c1,c3}_{v0,v1} c^{c2}_{a2} eta1^{a2}_{a1} a+(c0) a+(v0) a+(v1) a-(a0) a-(c2) a-(c1)
+1/4 a^{a0,a1}_{c1,c2} b^{c0,c1}_{v0,v1} c^{c2}_{a2} a+(a2) a+(v0) a+(v1) a-(a1) a-(a0) a-(c0)
-1/2 a^{a0,a1}_{c1,c2} b^{c0,c1}_{v0,v1} c^{c2}_{a2} eta1^{a2}_{a1} a+(v0) a+(v1) a-(a0) a-(c0)
+1/8 a^{a0,a1}_{c1,c2} b^{c1,c2}_{v0,v1} c^{c0}_{a2} a+(a2) a+(v0) a+(v1) a-(a1) a-(a0) a-(c0)
-1/4 a^{a0,a1}_{c1,c2} b^{c1,c2}_{v0,v1} c^{c0}_{a2} eta1^{a2}_{a1} a+(v0) a+(v1) a-(a0) a-(c0)