The document defines a set function v over subsets of a set N={1,2,3} that assigns values to singleton and composite sets. It then defines a vector x=(x1,x2,x3) and constrains the values of x to be consistent with v through linear inequalities and equations. It solves for the values of x1, x2, x3 that satisfy all the constraints, finding the solution x1=20, x2=60, x3=50. The document also discusses some properties and definitions related to set functions.