1/2 a^{a1}_{a0} b^{a2}_{v0} c^{v1,v2}_{a3,a4} eta1^{a4}_{a2} eta1^{a3}_{a1} a+(a0) a+(v0) a-(v2) a-(v1)
+1/4 a^{a1}_{a0} b^{a2}_{v0} c^{v1,v2}_{a3,a4} lambda2^{a3,a4}_{a1,a2} a+(a0) a+(v0) a-(v2) a-(v1)
-1/2 a^{a2}_{a1} b^{a3}_{v0} c^{v1,v2}_{a0,a4} eta1^{a4}_{a2} gamma1^{a1}_{a3} a+(a0) a+(v0) a-(v2) a-(v1)
-1/2 a^{a2}_{a1} b^{a3}_{v0} c^{v1,v2}_{a0,a4} lambda2^{a1,a4}_{a2,a3} a+(a0) a+(v0) a-(v2) a-(v1)