=====data Keyword 3=====
Postfix (reverse polish)

====Definition====
A mathematical notation wherein every operator follows all of its operands. For instance "3 + 4" would be written as "3 4 +". If there are multiple operators the operator is given immediately after its second operand; so the expression written "3 − 4 + 5" in conventional infix notation would be written "3 4 − 5 +"
====References====
http://en.wikipedia.org/wiki/Postfix_notation

=====data Keyword 3 Phase 2=====
Identification of chosen keyword.

====Definition====
Definition (in your own words) of the chosen keyword.

====References====
List any sites, books, or sources utilized when researching information on this topic. (Remove any filler text).

  * Reference 1
  * Reference 2
  * Reference 3


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

If you wish to aid your definition with a code sample, you can do so by using a wiki **code** block, an example follows:

<code c>
/*
 * Sample code block
 */
#include <stdio.h>

int main()
{
    return(0);
}
</code>

Alternatively (or additionally), if you want to demonstrate something on the command-line, you can do so as follows:

<cli>
lab46:~$ cd src
lab46:~/src$ gcc -o hello hello.c
lab46:~/src$ ./hello
Hello, World!
lab46:~/src$ 
</cli>