=====discrete Keyword 2=====
Intersection

====Definition====

Two sets A and B is the set that contains all elements of A that also belong to B (or equivalently, all elements of B that also belong to A), but no other elements.

Example:
    The intersection of the sets {1, 2, 3} and {2, 3, 4} is {2, 3}.

====References====

  * http://en.wikipedia.org/wiki/Intersection_(set_theory)
  * www.solitaryroad.com/c725.html
  * http://www.mathgoodies.com/lessons/sets/intersection.html

=====discrete Keyword 2 Phase 2=====
cartesian product

====Definition====
**Cartesian Product** is making one set that takes one from a set and pairs it with one value from another set. This is done for each of the values in each set.
Example:

  * {1, 2} * {up, down} = {(1, up), (1, down), (2, up), (2, down)}
  * {1, 2, left} * {left, right, up, down} = {(1, left), (1, right), (1, up), (1, down), (2, left), (2, right), (2, up), (2, down), (left, left), (left, right), (left, up), (left, down)}

====References====

  * http://en.wikipedia.org/wiki/Cartesian_product
  * ndp.jct.ac.il/tutorials/Discrete/node28.html 
  * www.mathcaptain.com/algebra/cartesian-product.html 

====Demonstration====

<cli>
lab46:~$ ./cartesian

Enter Array Size For Array A: 3
Enter Array A Elements:
1
2
4

Enter Array Size For Array B: 3
Enter Array B Elements:
5
7
9

Cartesian Product Of Array A & B:
A = {1,2,4}  &  B = {5,7,9}
A x B = {1,2} x {2,7}  x {4,9} = {(1,5), (1,7), (1,9), (2,5), (2,7), (2,9), (4,5), (4,7), (4,9)}
B x A = {4,9} x {2,7} x {1,2} = {(4,9), (4,7), (4,5), (2,9), (2,7), (2,5), (1,9), (1,7), (1,5)}
</cli>