TITLE: relation between set operations
QUESTION [8 upvotes]: I was wondering about the relation between complement of a subset, different between two subsets, union and intersection of subsets. Can we reduce the set of the above operations in a minimal way so that other operations can be represented by these "independent" operations? And how many ways to do this? 
For example, the intersection (or union) can be represented by complement and union (or intersection) in the same way as in De Morgan law.
But can we represent complement or difference in terms of union and intersection?
Thanks!

REPLY [3 votes]: We could also write set difference in terms of intersection and complement as : $A \cap B = A - (A - B)$. (I do also prefer $A - B$ to $A \setminus B$)
This expression comes handy when you are dealing with cardinality.