Greatest And Least Integer Principle
The greatest and least integer principles are rather straightforward and are used a few times in the Number Theory section of Mathonline.
Least Integer Principle
Definition: A nonempty set of integers that is bounded below must contain a smallest element.
Greatest Integer Principle
** Definition:** A nonempty set of integers that is bounded above must contain a largest element.
Example 1
Let's look at the set of positive integers, Z+ = {1, 2, 3, …}. Z+ is bounded below by 1, and hence, by the least integer principle, there must be a smallest element in the set, namely it is 1.