define sets which is are equal equevalent, joint and disjoint?

1. Sets are equal if they contain exactly the same members or elements

    {1,3,8,4} is equal to {8,1,4,3}

2. Sets are equivalent if they contain the same NUMBER of members 
   or elements but not necessarily the same members or elements.

    (1,3,8,4} is equivalent to {7,8,5,1}

3. Sets are joint if they contain at least one element in common.

   {1,3,8,4} and {3,9,1,7} are joint sets.

4. Sets are disjoint if they have no member or element in common.

   (1,3,8,4} and (2,4,7,5} are disjoint sets.

Edwin