=====discrete Keyword 3=====
regular expression

====Definition====
Regular expressions are commands that match a pattern or characters in a string of characters or words. Some of the  regular expression commands are the ^ that matches the beginning of a line, the $ matches the end of line, the \< matches the beginning of the line, \> matches the end of the word, . matches any single character, * 0 is 0 or more of the previous character or whatever you put in front of the *, [] matches any of the characters enclosed, [^ ] does not match any of the characters enclosed. Then there is also extended regular characters or egrep. Those are () which is like \( \), | which means or and + which matches 1 or more of the previous character. Usually you have to use a combinations of these to get what you want.

====References====

  * http://en.wikipedia.org/wiki/Regular_expression
  * notes from unix/linux class

=====discrete Keyword 3 Phase 2=====
combination

====Definition====

A combination is a set containing a certain number of objects that have been selected from another set. In combinations, the order of the elements does not matter.
====References====
List any sites, books, or sources utilized when researching information on this topic. (Remove any filler text).

  * wikipedia
  * class






====Demonstration====
Demonstration of the indicated keyword.

Example:
  If you have three people Ted, Sue and John there 6 different ways or combinations you can order them. 
  Ted, Sue, John; 
  Ted, John, Sue;
  Sue, John, Ted;
  Sue, Ted, john;
  John, Sue, Ted; 
  John, Ted, Sue;