 x1*x3*x4*x5*x6*x7+x2*x3*x4*x5*x6*x7+x1*x3*x4*x5+x1*x3*x4*x6
+x1*x5*x6*x7+x2*x3*x4*x5+x2*x3*x4*x6+x2*x5*x6*x7+x1*x3*x4
+x2*x3*x4+x1*x5+x1*x6+x2*x5+x2*x6+x1+x2
