sets set contains number of valuesin no particular order the values within the set are distinct from one another generally set implementations tend to check that value is not in the set before adding itavoiding the issue of repeated values from ever occurring this section does not cover set theory in depthrather it demonstrates briefly the ways in which the values of sets can be definedand common operations that may be performed upon them the notation { defines set whose values are listed within the curly braces given the set defined previously we can say that is member of denoted by aand that is not member of denoted by often defining set by manually stating its members is tiresomeand more importantly the set may contain large number of values more concise way of defining set and its members is by providing series of properties that the values of the set must satisfy for examplefrom the definition { | the set contains only positive integers that are even is an alias to the current value we are inspecting and to the right hand side of are the properties that must satisfy to be in the set in this examplex must be and the remainder of the arithmetic expression / must be you will be able to note from the previous definition of the set that the set can contain an infinite number of valuesand that the values of the set will be all even integers that are member of the natural numbers set nwhere { finally in this brief introduction to sets we will cover set intersection and unionboth of which are very common operations (amongst many othersperformed on sets the union set can be defined as follows { or }and intersection { and bfigure demonstrates set intersection and union graphically given the set definitions { }and { the union of the two sets is { }and the intersection of the two sets is { both set union and intersection are sometimes provided within the framework associated with mainstream languages this is the case in net where such algorithms exist as extension methods defined in the type system linq enumerable as result dsa does not provide implementations of