public class Sets {

/*------------------------------------------------------------*/
    /**
     * Function isetIsEmpty(int theSet) returns true whenever
     * the set 'theSet' is empty.
     */
    static boolean isetIsEmpty(int theSet) {

    }

/*------------------------------------------------------------*/
    /**
     * Function isetInsertElement(int theElement, int theSet) 
     * inserts an element 'theElement' into the set 'theSet'
     * and returns the resulting set.
     */
    static int isetInsertElement(int theElement, int theSet) {

    }

/*------------------------------------------------------------*/
    /**
     * Function isetUnion(int set1, int set2)
     * returns the set union of sets 'set1' and 'set2'.
     */
    static int isetUnion(int set1, int set2) {

    } 

/*------------------------------------------------------------*/
    /**
     * Function isetDiff(int set1, int set2)
     * returns the set difference of sets 'set1' and 'set2',
     * i.e. 'set1' \ 'set2'
     */
    static int isetDiff(int set1, int set2) {

    } 

/*------------------------------------------------------------*/
    /**
     * Function isetIntersection(int set1, int set2)
     * returns the set intersection of sets 'set1' and 'set2'.
     */
    static int isetIntersection(int set1, int set2) {

    } 


/*------------------------------------------------------------*/
    /**
     * Function isetPrint(int theSet, String theSetsName)
     * prints all elements of 'theSet' together with the string
     * 'theSetsName' (for identification purposes).
     */
    static void isetPrint(int theSet, String theSetsName) {

    }


/*------------------------------------------------------------*/


    public static void main(String[] args) {

        // Define three variables representing empty sets 
	int set1 = 0;
        int set2 = 0;
        int set3 = 0;
	
	// Check if set1 is empty and print result

	// Insert element 15 into set1

	// Insert element 5 into set1

	// Check if set1 is empty and print result

	// Output the elements contained in set1

	// Insert element 5 into set2

	// Insert element 8 into set2

	// Calculate set3 = union of set1 and set2

	// Output the elements contained in set3

	// Calculate set3 = intersection of set1 and set2

	// Output the elements contained in set3

	// Calculate set3 = difference of set1 and set2 (set1 \ set2)

	// Output the elements contained in set3

    }

}