Intersection (X,Y)
Returns a set theoretic intersection of X and Y (X and Y are vectors pretending to be sets)
IsIn (x,X)
Returns true if the element x is in the set X (where X is a vector pretending to be a set)
MakeSet (X)
Returns a set where every element of X appears only once
SetMinus (X,Y)
Returns a set theoretic difference X-Y (X and Y are vectors pretending to be sets)
Union (X,Y)
Returns a set theoretic union of X and Y (X and Y are vectors pretending to be sets)