public void minus(Set x){
  if (size() > x.size()) {
    Enumeration elements=x.elements();
    while (elements.hasMoreElements())     remove(elements.nextElement());
  }
 else {
    Enumeration elements=elements();
    Object a;
    while (elements.hasMoreElements()) {
      a=elements.nextElement();
      if (x.in(a))       remove(a);
    }
  }
}

public void minus ( Set x ) { if ( size ( ) > x . size ( ) ) { Enumeration elements = x . elements ( ) ; while ( elements . hasMoreElements ( ) ) remove ( elements . nextElement ( ) ) ; } else { Enumeration elements = elements ( ) ; Object a ; while ( elements . hasMoreElements ( ) ) { a = elements . nextElement ( ) ; if ( x . in ( a ) ) remove ( a ) ; } } }
destructively modify this so that all elements in x are removed . if | this | > | x | we iterate over the elements in x , removing them all from this . otherwise , we iterate over the elements in this , removing any that are in x .
